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Ube IRural ZcxUBoo\{ Series 

Edited by L. H. BAILEY 



THE CORN CROPS 



Eije Eural WtxUBook Series 

Lyon and Pippin, Pkinciples of Soil Man- 
agement. 
G. F. Warren, Elements of Agriculture. 

A. R. Mann, Beginnings in Agriculture, 
J. F. Duggau, Southern Field Crops. 

B. M. Duggar, Plant Physiology, with 
Special Reference to Plant Production. 

G. F. Warrkn, Farm Management. 

M. W. Harper, Animal Husbandry for 

Schools, 
E. G. Montgomery, The Corn Crops. 
H. J. Wheeler, Manures and Fertilizers. 




(Frontispiece) 



TYPICAL PLANTS OF DENT CORN. 



THE CORN CROPS 



A DISCUSSION OF MAIZE, KAFIKS, AND 

SOEGHUMS AS GROWN IN THE 

UNITED STATES AND CANADA 



BY 



E. G. MONTGOMERY 

PROFESSOR OF FARM CROPS IN THE NEW YORK 

STATE COLLEGE OF AGRICULTURE AT 

CORNELL UNIVERSITY 



REVISED EDITION 



THE MACMILLAN COMPANY 
1920 

All rights reserved 



\ 



c^'^^ 

^^^ 



Copyright, 1913, 1920, 

Bt the macmillan company. 



Set up and electrotyped. Published August, 1913. Reprinted 
July, 1915; February, August, 1916. 
Revised edition, February, 1920. 



FEB ^5 t920 



Ncrhjooli PwBS 

J. S. Cushing Co. — Berwick & Smith Co. 

Norwood, Mass., U.S.A. 



'C1.A559807 



PREFACE 

In planning a course of study, the author must needs lay- 
out a working plan. He should know the philosophy of his 
subject and its relation to other sciences. Field crops like 
other applied sciences has little pure science of its own, but 
is rather based on other sciences. The subject is not erected 
so much as a superstructure on other sciences, but rather 
moves in a progressive way, between them, abstracting such 
elements from each as contribute to the art of producing the 
crop under consideration. 

The outline on page vi is an attempt to illustrate the log- 
ical order of study and relation of other sciences to the 
study of Crop Production. 

The outline below indicates that a knowledge of all the 
"earth sciences" is fundamental to a study of crop produc- 
tion, hence a student should have a general course in all 
these sciences with special emphasis on botany (physiology 
and ecology) and chemistry. 

In regard to a particular crop like maize, this knowledge 
needs special interpretation and application, which is the 
function of field crops instruction. 

The ability to yield with our ordinary crops is far above 
the average yield. With maize 200 bushels per acre have 
been produced under optimum conditions, while the average 
yield is about 26 bushels. Therefore the study of maize 
production is principally a study of those factors which 
serve to hinder full development, and thus limit production, 



VI 



PREFACE 



Outline Plan showing the Relation of the Sciences to 
THE Various Phases of Crop Production 



Department 
GIVING Work 


Character of Work 


Basic Science 
involved 




The Plant 




1. Botany 


Study of normal 


Botany 


Field crops treats 


plants, their histol- 




application to 


ogy, physiology. 




special crop 


etc., and normal 
environmental re- 
quirements 

Survey 




2. Field crops will 


Survey of natural con- 


Ecology (Botany) 


consider the 


ditions as related to 


Meteorology 


application of 


the normal, under 


Geology 


the sciences to 


which it is proposed 


(Geography) 


the particular 


to cultivate the 




crop . under 


plant 




consideration 


Adaptation 




3, (a) Field crops 


(a) Adaptation of 


(a) Plant breeding 


(Plant breed- 


plant to climate 


(natural and 


ing) 


and soil 


artificial se- 
lection) 
Ecology 


(6) Soils 


(6) Adaptation of soil 


(6) Chemistry 




to plant 


Physics 
Bacteriology 




Protection 




4. (a) Field crops ; 


(a) Farm practice in 




also farm 


preparing and 




practice 


planting fields 




for (6) and 


in order to pro- 




(c) 


tect against 
weeds, drought, 
rain, etc. 




(6) Botany (the 


(6) Against fungous 


Botany 


diseases) 


diseases 




(c) Entomology 


(c) Against insects 


Entomology 


(the in- 






sects) 







PBEFACE VU 

and the art of maize production is removing or modifying 
these limiting factors. 

Practically the whole problem is involved in securing 
a perfect harmony between the plant and its environ- 
ment. 

Environment may be classed as climatic factors and soil 
factors. Over climate we exercise little or no control. 
Either the plant must be adapted to suit the climate or its 
production is limited only to those regions where a natural 
climate is found to which the plant is suited. The natural 
precipitation is about the only factor assigned to climate, 
the effect of which can be modified. Where precipitation is 
excessive, land can be drained, or where deficient, methods 
of storing the moisture in soil may be adopted. However, 
within certain limits there is usually an optimum rainfall 
which favors the largest production. 

Soil environment, however, is subject to modification in a 
very large degree. If proper elements are present in the 
soil but in an insoluble state, solvents may be added as 
decaying organic matter, or air be admitted by tillage and 
the bacterial flora increased. If the proper mineral ele- 
ments are not present or present in an unavailable form, 
these elements may be added to the soil, until a normal 
state of fertility is produced. 

After the conditions of adaptation of both plant and soil 
have been fulfilled so far as practicable, and seed has been 
planted in suitable soil, it is then necessary to protect. 
Protection is the principal reason for cultivation. To facil- 
itate cultivation, systems of planting have been devised, as 
the distribution of the plants in rows, drills, or checks, in 
furrows or on the level surface. 

Protection against insect enemies and fungous diseases is 
also an important part of production, and is one of the 
reasons for the practice of rotations. 



Vlii PREFACE 

A large share of farm practice has to do with modifying 
the soil environment and protection of the crop. 

THE PHILOSOPHY OF CKOP PRODUCTION 

The art of crop production is based on an application of 
the sciences, (a) to producing a natural condition as per- 
fectly adapted as possible to the needs of some particular 
crop, or (5) the adaptation of the crop to certain natural con- 
ditions. 

The study of crop production for any large region in- 
volves a study of four general phases of the subject, as: 
1. The plant, its structure, j)hysiology, and normal require- 
ments. 2. A general survey of the region where it is pro- 
posed to cultivate the plant, to note how the natural conditions 
found correspond to the needs of the plant. 3. The adapta- 
tion of the plant on the one hand to natural conditions and 
adaptation of soil on the other to the needs of the plant. 
Maximum production is obtained when perfect adaptation is 
secured. 4. Protection is necessary against other indige- 
nous plants, fungous diseases, and insects. 

The treatment of subjects in the text follows practically 
the above plan. The plan also allows a wider use of the 
text for different classes of students. The first two divisions 
are technical and should only be studied by students who 
have training in the sciences involved. With less advanced 
students the work may begin with Part III, Adaptation. 
The third and fourth divisions deal with the more practical 
phases of production and are written in a more popular style, 
this double use of the book being in mind. 

Acknowledgments. — For furnishing photographs used 
in illustrating the text, the author is indebted to Mr. Carle- 
ton R. Ball, Mr. C. W. Warburton, and Mr. C. P. Hartley, 
all of the Bureau of Plant Industry. A large number of 



PBEFACE ix 

photographs secured from the Nebraska Experiment Station 
have also been used, Professor T. A. Kisselbach furnishing 
several of these. Also the Portland Cement Co., Deere and 
Co., Janesville Machine Co., Planet Jr. Co., and Sandwich 
Manufacturing Co. have furnished illustrative material. 



E. G. MONTGOMERY. 



Ithaca, N.Y., 
January 1, 1913, 



TABLE OF CONTENTS 

PART I 
CORN 

CHAPTER I 

Production and Distribution of Indian Corn . . . 1-11 
Relative importance of corn and other crops in the 
world, 1 — Corn crop of the world, 3 — International trade 
in corn, 4 — Relative value of different crops in the United 
States, 6 — Development of corn production in United 
States, 7 — Production by states, 7 — Production by sec- 
tions and market movement, 11. 

SECTION I 
THE CORN PLANT 

CHAPTER II 
Origin and Classification ....... 15-25 

Geographical origin, 15 —Biological origin, 16 — Classi- 
fication of maize in groups, 20. 

CHAPTER III 
Description of the Corn Plant ...... 26-37 

The root, 26 — The stem, 31 — Tillers, 33 — Leaves, 33 
— The flower, 36 — The ear, 37. 

CHAPTER IV 

Physiology of Corn 38-56 

Turgidity, 39 — Tension, 40 — Mechanical tissue, 40 — 
The composition of a corn plant, 42 — The absorption of 
water, 45 — The giving off of water, 45 — Assimilation, 
47 — Growth, 48 — Reproduction, 49 — Pollen, 50 — Style, 
51 — Fertilization, 52. 

xi 



Xii TABLE OF CONTENTS 

SECTION II 

PRODUCTION AS RELATED TO CLIMATE 
AND SOILS 



CHAPTER V 

PAGES 

Relation of Climatic Factors to Growth . . . 57-67 
Relation of climatic factors to growth, 58 — Length of 
growing season, 59 — Relation of sunshine to growth, 61 
— Relation of rainfall to growth, 64. 

CHAPTER VI 

Relation of Soils to Growth 69-73 

Causes of low production, 70 — Classification of corn 
soils in the United States according to productiveness, 70. 



SECTION III 

IMPROVEMENT AND ADAPTATION OF THE 
CORN PLANT, AND ENVIRONMENT 

CHAPTER Vn 

Early Culture 77-84 

Development of varieties, 78 — Early methods of modi- 
fying varieties, 80 — Natural selection and acclimatization 
in producing varieties, 83. 

CHAPTER Vni 

Improvement of Varieties 85-93 

Type of ear, 85 — Type of plant, 86 — Systems of selec- 
tion, 88 — Results with mass and pedigree selection, 89 — 
Selection for composition, 91. 



TABLtit OF CONTENTS xiii 

CHAPTER IX 

PAGES 

Methods of Laying out a Breeding Plat . . . 94-100 

How to conduct a breeding plat, 95 — The second 
year's work, 98 — Continuation of breeding, several 
plans, 99. 



CHAPTER X 

Results with Hybridization 101-116 

Degrees of Relationship, 101 — Xenia, 103 — Mendel's 
laws, 104^ Dominant and recessive characters, 105 — 
Hybridization, effect on growth, 107 — Self-fertilization, 
107 — Pure strains, or biotypes, 109 — Crossing biotypes, 
111 — Crossing varieties. 111 — Isolating high-yielding 
biotypes, 115. 



CHAPTER XI 

Acclimation and Yield 117-121 

Effect of environment on the corn plant, 118 — Effect 
of previous environment on yield, 119 — Adaptation of 
the soil, 121. 

CHAPTER XII 

Cropping System in Relation to maintaining the Yield 

OF Corn 122-128 

Cropping systems, 122 — l^storing production, 123 — 
Maintaining production, 124 — Rotations for corn grow- 
ing, 127. 



CHAPTER XIII 

Organic Matter . 129-134 

Farmyard manure for corn, 130. 



XIV TABLE OF CONTENTS 



CHAPTER XIV 

PAGES 

Mineral Matter 135-150 

Fertilizers for corn, 138 — Fertilizer mixtures for corn, 
142 — When it pays to fertilize for corn, 144 — Nitrogen, 
146 — Lime, 147. 

CHAPTER XV 

Regulating the Water Supply . . • . . 161-157 
Erosion, 154 — Drainage, 157. 



SECTIOK IV 
CULTURAL METHODS 

CHAPTER XVI • 

Preparation and Planting 161-196 

The old corn stalks, 161 — Time of plowing, 163^ 
Depth of plowing, 163 — Subsoiling, 166 — Preparation 
of plowed land, 166 — Planting the seed, methods, 168 

— Sowing corn for forage, 171 — Checking and drilling, 
172— Time of planting, 172 — Rate of planting, 176 — 
Adjustment of corn plants, 178 — Economic value of 
tUlers, 179 — Rate of planting on different soils, 180 — 
Methods of distribution of plants, 181 — Width of rows, 
182 — Yield of forage, 183 — Effect on composition, 183 

— Choice of a variety, 184 — Preparing seed for plant- 
ing, 190 — Causes of poor germination, 190 — Germina- 
tion tests, 192 — Importance of strong vitality, 194 — 
Grading seed, 195 — Calibrating the planter, 195. 

CHAPTER XVII 

The Principles of Interculture ..... 197-213 

Tillage machinery, 197 — Methods of tillage compared, 
206 — Water-loss from fallow soil, 207 — Evaporation 



TABLE OF CONTENTS 



XV 



under corn crop, 208 — The effect of weeds, 208 — 
Depth and frequency of cultivation, 209 — Growing corn 
for silage, 212. 

CHAPTER XVIII 



Animal and Insect Enemies 

Birds, 214 — Rodents, 214 
of corn, 220. 



Insects, 216 — Diseases 



214-221 



CHAPTER XIX 

Harvesting the Corn Crop . . . . . 

Time of harvesting, 224 — Relative proportion of parts, 
226 — Composition of parts, 226 — Relative value of 
parts, 227 — Time of harvesting for silage, 229 — Meth- 
ods of harvesting, 230 — -Comparative cost of harvesting 
methods, 241 — Shrinkage in curing fodder, 243 — Mar- 
keting, 245. 



222-248 



Uses of Corn 



CHAPTER XX 



249-252 



CHAPTER XXI 



Show Corn .... 

Growing show corn, 257. 



. 253-258 



CHAPTER XXII 

Sweet Corn or Sugar Corn 259-275 

Varieties and types, 259 — Varieties, 262 — Seed, 263 
— Selecting and curing sweet corn, 264 — Growing sweet 
corn for canning, 266 — Market sweet corn, 270 — Forc- 
ing sweet corn, 273 — Sweet corn in the home gar- 
den, 274. 



XVI 



TABLE OF CONTENTS 



PART II 

SORGHUMS 

CHAPTER XXIII 



The Sorghum Plant 



PAGES 

279-291 



Geographical origin, 280 — Botanical classification, 281 
— The sorghum plant, 285 — Physiology of sorghums, 
286 — Keproduction, 287 — Fertilization , 287 — Natu- 
ral crossing, 287 — Climate and soils, 288 — Sorghum 
types, 290. 



CHAPTER XXIV 

The Saccharine Sorghums 



Introduction into the United States, 293 — How the 
crop is utilized, 296 — Classification of sweet sorghums, 
296. 



293-300 



CHAPTER XXV 

The Non-saccharine Sorghums 

Historical, 301 — Region where cultivated, 303 — Sta- 
tistics of culture, 304 — Kafir, 308— Durra, 310 — 
Shallu, 313— Kowliang, 314. 



301-314 



CHAPTER XXVI 



Cultural Methods for Sorghums . 

Growing sorghums for grain, 315 - 
for forage, 321. 



Growing sorghums 



315-323 



TABLE OF CONTENTS 



XVll 



CHAPTER XXVII 



Utilizing the Sorghum Crop ...... 324-327 

Poultry food, 325 — Soiling or green feed, 325 — Pas- 
ture, 325 — Sorghum mixtures for pasture, 326 — Sor- 
ghum for silage, 326 — Sorghum poisoning, 327. 

CHAPTER XXVm 



Sorghum for Sirup-making . . , . , 
Time of harvesting, 328 — An average yield, 329. 



328-330 



CHAPTER XXIX 



Broom Corn . . , . . . . » . 

Historical, 331 — Statistics of culture, 331 — Varieties, 
333— Planting, 336 — Tillage, 336— Time of harvest- 
ing, 337. 



331-340 



PART I 

CORN 



CORN CROPS 

CHAPTER I 

PRODUCTION AND DISTRIBUTION OF INDIAN 

CORN 



The corn crops, as understood in this book, are the de- 
rivatives of two group-species : of Zea Mays, the Indian 
corn or maize ; and of Andropogon Sorghum, the sorghum 
and kafir series. The former is a plant-group of the West- 
ern Hemisphere and the latter of the Eastern Hemisphere. 
The maize products are used both for human and stock 
food, but the sorghum products are employed in this 
country mostly for the feeding of animals. 

1. Relative importance of corn and other crops in the 
world. — The hay and forage crop is the most important 
crop of the world, but this is made up of a great variety 
of plants. The jdeld in milhons of tons of the world's 
most important plants is shown in the following diagram : — 

World's Crops of the Most Important Food Plants. Average 
FOR 5 Years, 1906-1910 




CORN CROPS 





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PRODUCTION OF INDIAN CORN 



3 



In total value, the world's wheat crop probably ranks 
first, the potato crop second, and the corn crop third. 

2. Corn crop of the world. — The following tables 
(I, II) give the world's production of corn for five years 
1906-1910. The data is abstracted from the Year Books 
of the United States Department of Agriculture : — 

TABLE II 

Percentage of World's Corn Crop produced by the Con- 
tinents, AND Principal Corn-producing Countries. 
For 5 Years, 1906-1910 



Continent 


1906 


1907 


1908 


1909 


1910 


Average 


North America 
Europe . . 
South America 
Africa . . . 
Australia . 


77.25 

15.34 

5.03 

2.15 

.23 


80.56 

14.34 

2.29 

2.49 

.32 


78.74 

14.68 

3.98 

2.36 

.24 


77.06 

15.04 

5.20 

2.42 

.28 


76.88 

16.02 

4.55 

2.25 

.29 


78.09 

15.08 

4.20 

2.35 

.28 


Total . . 


100.00 


100.00 


100.00 


100.00 


100.00 


100.00 





Principal 


Countries 






United States 


73.85 


75.79 


73.94 


71.74 


71.67 


73.39 


Austria- 














Hungary . 


5.31 


5.74 


5.28 


5.92 


5.97 


5.64 


Mexico . . 


2.77 


4.09 


4.15 


4.77 


4.73 


4.10 


Argentina 


4.91 


2.09 


3.77 


4.98 


4.35 


4.02 


Italy . . . 


2.34 


2.58 


2.65 


2.79 


2.52 


2.57 


Roumania 


3.29 


1.68 


2.18 


1.97 


2.57 


2.34 


Egypt . . . 


1.64 


1.90 


1.80 


1.82 


1.74 


1.78 


Russia 














(European) 


1.77 


1.48 


1.69 


1.11 


1.91 


1.59 


Total . . 


95.88 


95.35 


95.46 


95.10 


95.46 


95.43 



- The world's corn crop varies from about three and one- 
half billion bushels to about four biUion bushels, or a 
variation of 12 per cent. This rather wide variation is 



4 



CORN CROPS 



due to the fact that more than one-half the world's corn 
crop is concentrated in one section of the United States. 

The comparative production is brought out more clearly 
in Table II, based on percentage production. 

From the tables, it appears that North America pro- 
duces 78 per cent of the world's corn crop, Europe pro- 
duces 15 per cent, leaving only 7 per cent for the other 
continents. The United States produces about 73 per 
cent of the world's crop, Austria-Hungary 5.6 per cent, 
Mexico 4.1 per cent, and Argentina 4 per cent, the four 
countries combined producing 87 per cent of the world's 
crop. 

TABLE III 

Showing Corn exported by Countries and Percentage 
OF Total World's Exports for 5 Years, 1906-1910, 
Inclusive 



Country 


Average Annual 
Export 
Bushels 


Percentage op 
Total Exports 


Argentina . . . 
United States . . 
Roumania 




83,569,388 
62,596,444.2 
33,124,210.4 
23,255,489.2 
7,007,737.8 
6,718,712 
6,021,984.4 
3,054,136.2 
328,352.6 
210,674.2 
8,703,035 


35.66 
26.64 
14.15 


Russia (European) 
Belgium .... 




9.90 
2.93 


Netherlands . 




2 83 


Bulgaria .... 




2.55 


Servia .... 




1 35 


Austria-Hungary . 
Urueruav .... 




.14 
.09 


Other Countries 




3.75 


Total . . . 


234,590,164.0 


100.00 









3. International trade in corn. — The net exports and 
imports indicate those countries producing a surplus, and 
those countries as well that must buy. Table III shows 



PRODUCTION OF INDIAN CORN 



that Argentina furnishes about 35 per cent of the world's 
export corn and the United States only 26 per cent. 
Table IV shows that Argentina exports 55 per cent of the 
crop produced, while the United States exports only 2.29 
per cent. This country can hardly be classed as a sur- 
plus corn country, though the small percentage exported 
furnishes one-fourth of the world's export corn. The prin- 
cipal importing country is the United Kingdom, taking 
36 per cent of the world's trade in corn, and Germany 14 
per cent more, the two taking one-half the corn trade. 

TABLE IV 

Showing Percentage op Total Corn Crop exported by 
THE Principal Exporting Countries, 5-Year Average, 
1906-1910, Inclusive 



GOUNTRT 


Production in 
Bushels 


Exportation in 
Bushels 


Percentage of 
Crop 


United States . . 
Argentina . . . 
European Russia . 
Roumania . . . 
Bulgaria .... 


2,725,367,400 

151,015,000 

59,831,200 

88,163,400 

22,281,800 


62,596,444 
83,569,388 
23,255,489 
33,124,210 
6,021,984 


2.29 
55.33 

38.86 
37.57 
27.02 



Europe consumes about 91 per cent of the world's corn 
trade. This corn is largely used for feeding live-stock, 
but also in the brewing industry. 

Exportation of corn from the United States is decreasing. 
The maximum exportation from this country was during 
the 5-year period 1896-1900, when it reached an annual 
average of 9.4 per cent. The present decrease in expor- 
tation, indicates that home consumption in the United 
States will soon equal production. In recent years some 
corn has been imported at both Atlantic and Pacific ports. 



CORN CBOPS 



TABLE V 

Showing Corn imported by Countries and Percentage of 
Total World's Imports for 5 Years, 1906-1910, In- 
clusive 



Country 


Av. Annual Import of 
Corn in Bu. for 5 Yr. 


Percentage op 
Total Import 


United Kingdom . . . 
Germany ..... 

Netherland . . . . . 

Belgium ...... 

France . . » . . . 
Denmark » . . . . 

Canada ...... 

Italy „ o . . . . . 

Spain . 

Austria-Hungary . . . 
Switzerland ..... 

Mexico ...... 

Cuba ....... 

Portugal ...... 

Norway ...... 

Egypt ...... 

Sweden ...... 

Russia . . . . . . 

British South Africa . . 
Other Countries . . . 


84,835,078 
34,189,007 
24,836,943.4 
21,984,982.6 
13,510,287.2 
12,705,123.8 
10,809,151.8 
7,737,137.8 
4,891,501 
4,170,578.2 
2,996,767.6 
2,738,086.8 
2,546,576.8 
1,169,913.4 
1,043,998 
662,416.4 
386,611 
329,755.6 
147,452.2 
3,453,661.4 


36.07 

14.53 

10.56 

9.36 

5.74 

5.45 

4.59 

3.29 

2.08 

1.77 

1.27 

1.16 

1.08 

.49 

.44 

.28 

.16 

.14 

.06 

1.46 


Total ..... 


235,145,030.0 


100.00 



CORN PRODUCTION IN THE UNITED STATES 

4. Relative value of different crops in the United 
States. — The corn crop is more valuable than any two 
other crops in the United States. The value of all wealth 
produced on farms, including that derived from cereals, 
hay, cotton, live-stock, forests, and fruit, amounts to 
7955 millions of dollars. The corn crop alone furnishes 
about one-fifth of this annual wealth. 



PRODUCTION OF INDIAN CORN 



Relative Farm Value of Principal Crops in the United States. 
Average for 5 Years, 1906-1910 



Crop 

Com 
Hay 
Cotton 
Wheat 
Oats 
Potatoes 
Barley- 
Tobacco 



Value in 
Millions 

S1431 
681 
670 
690 
367 
187 
92 
82 




As a result of the world war prices, there has been an 
enormous increase in crop values. Cotton, due to high 
prices, has surpassed hay in value, and tobacco has sur- 
passed the barley crop. The average values for the three 
years 1916-1917 and 1918 are as follows : — 
Corn . . S3,243 millions Oats . 

Cotton . . 1,434 millions Potatoes 

Hay . . 1,434 millions Tobacco 

Wheat . . 1,390 millions Barley 

5. Development of corn production in United States : — 



$936 miUions 
480 millions 
281 millions 
212 millions 



TABLE VI. Average 


Production at Different Periods 






Bushels 

(000 OMITTED) 


Yield 


Total 


Value 


Years 


Acres 


PER Acre 
Bushels 


Value (000 

OMi'lTED). $ 


Bushel 
Cts. 


1849 . . 




592,071 








1859 . . 




838,793 








1867-1876 


38,688,449 


1,011,535 


26.2 


457,000 


46.5 


1877-1886 


68,408,900 


1,575,626 


25.1 


625,623 


40.3 


1887-1896 


74,290,879' 


1,800,271 


24.0 


633,694 


36.6 


1897-1906 


87,971,235 


2,240,363 


25.4 


869,575 


39.0 


1907-1916 


103,845,100 


2,705,348 


26.0 


1,633,342 


61.0 


1916 . . 


105,296,000 


2,566,927 


24.4 


2,280,729 


88.9 


1917 . . 


116,730,000 


3,065,233 


26.3 


3,920,228 


127.9 


1918 . . 


107,494,000 


2,582,814 


24.0 


3,528,313 


136.6 



CORN CROPS 



Per Cent 
Shipped out op 

County 
WHERE Grown 


is! 

•H 1^ 


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> 








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fig 




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Is! 


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„ COCOI>(NCiOcOCOOOOOCO'=fOiOLOCOI>COCO 
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^ 1> CO^ 1-H CO^ CO^ CO^ CO^ (N Ci^ (M^ CO 1> CO^ CO^ 1-H iO_ CO i-l rH c^^ 

g co" rf cT oo" o" t^" t-h" c^" co" rH oo" co" lo" co" o" i> o" oo" I>" Tf 

rn iO00c00000t^CiC0C0O00ThC50iC0iOC0TJH»OC0 

COCOi-Hi— IrH rH i-H 


14 


t^0q,-(LOOC0^C^L0C0(MOT^00cOc0(NI>l>»O 

■7, ooiC^i-H-<*cqcooioco(M'*TticoioOTjH'*OrH 

^ 05^ (N ^^ CO^ Cl C^^ l> cO__ rH cO^ l> 00^ rH o^ (N q_ 05_ O^ O ^^ 

§ lo CO (n" T-T T^" co" Lo Oi" 1-h" co" o" lo" lo" >o" ca" i-h" o" oT lo" ■*" 

CQ iO(M(MOt>COTjHcOT-iC500iOiOiOiOiOiO^^'* 

^ COCOC^(Mi-HrHT-li-l,-l 


1 






Illinois' . . , . 

Iowa 

Missouri . . . 
Nebraska . . . 
Indiana . . „ „ 
Kansas « . „ . 
Texas .... 
Ohio ..... 
Oklahoma . '. . 
Kentucky . , „ 
Tennessee . . . 
Michigan . . . 
South Dakota . . 
Minnesota . . . 
Pennsylvania . . 
Wisconsin . . . 
Georgia .... 
Arkansas . . . 
Virginia .... 
Alabama 



PBODUCTION OF INDIAN CORN 



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(N rH CO rH 



(X)(^^M(Ncqu^coqcoqGOc^cqqcoqqcqcoLqcoqpcqcqtqcoq 
05I>o6l>^^oc^rHld(^oo6a)^^(^Qcococ^'c6rHT-^^<Ioioo6td^ 

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C<liOOOtOt^OO(NCOCOi--<OOOOCOOO(NLOTtHOC^i-H(N0505i-l>OCOC^ 

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(N CO r-^ (M" 



THcoTHrH,-lO(^^cO'-^colO(^^lO(^^Tt^(^^l>Tt^Tt^l>ooOl-l05 

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CO rJH CO-OO COI>tO(MCDi-H(NTH 



r> i> lo 1-1 

lOCOOOI>(MaiOt>>OlO'^>OtO(MTHTHi-lrHi-H 

COt^tOtMCD'-ifNTH 
<N (N T-l 1-1 

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tOCOOCOi-iC51>l>05iOOO^COOcOI>(MMiO(Ni-HOOCOCO<rOiOiOiO 

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l>COCOi— l00>OI>OC000(N05Oi— iU^rHCOOOI>LOiOt>rtlCO(MOOO(N 

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C^ , . ^ . . o . . . . „ o , . ^ . . , . o , . . . . 

llllp^.llllti i il?ti 111 i-.|l II 



10 



CORN CROPS 




Fig. 1. — Corn production in the United States. 

Corn per square mile, census 1900: Black shading, more than 3200 bu. ; next 
shading, 640 to 3200 bu. ; next-to-bottom shading, 64 to 640 bu. ; bottom shading, 
less than 64 bu. 




Fig. 2. — Map showing average yield per acre, average farm price per 
bushel, and average shipment out of county where grown for grand 
divisions of the United States. 



PRODUCTION OF INDIAN CORN 



11 



6. Production by states. — Table VII gives the most 
important data summarized on the production of corn by 
states. This table is arranged according to rank by 
states and shows that the eight leading states produced 
about 63 per cent of the total crop. 

7. Production by sections, and market movement. — The 
following summary, together with Fig. 2, gives a definite 
idea of the relative production in different sections of the 
country, and also the comparative market movement. 
The available data is corn shipped out of the county where 
grown, and does not always mean that the corn leaves 
the state, but indicates the surplus corn in the hands of 
growers. Most of the lesser corn states consume more 
corn than they raise, while in the principal corn-belt, most 
of the corn put on the market leaves the state, and is 
utilized in manufacturing corn products or shipped to other 
regions .' — 

TABLE VIII 

Table showing Percentage op Entire Corn Crop pro- 
duced BY Each Grand Division of the United States 
AND the Market Movement. 5-Year Average, 1906- 
1910, Inclusive 







Per Cent 






Per Cent 

Total 

Crop of 

Each G. 

Div. 


Grand 
Division 


Total Pro- 
duction 


OF Total 
Produc- 
tion 


Amount 

SHIPPED 


Per Cent 
OF Total 

SHIPPED 






SHIPPED 
















SHIPPED 


North Atlantic 


90,543,473 


3.32 


5,817,676 


.96 


6.42 


South Atlantic 


223,216,236 


8.19 


20,134,990 


3.30 


9.02 


North Central 












East Miss. 












River . . 


777,297,616 


28.53 


255,966,226 


41.98 


32.93 


North Central 












West Miss. 












River . . 


1,027,233,955 


37.69 


249,041,882 


40.84 


24.24 


South Central 


597,806,892 


21.93 


77,974,324 


12.78 


13.04 


Far West . . 


9,329,243 


.34 


810,453 


.14 


8.68 


Total . . 


2,725,427,415 


100. 


609,745,551 


100. 





12 COBN CROPS 

Revised data on production. In maldiig a few revisions in the 
text at this time (1919) it seems advisable to make no changes 
in the original tables in the first edition (except Table VII). 
The original tables were based on data for the years 1906-1910 
and 1900-1909. The figures would not be materially changed 
for the next period 1910-1914. World data are incomplete for 
the past four years, 1914-1918, due to the world war. Values 
have also been abnormally increased and would not be compa- 
rable with normal conditions. It wiU be of interest, however, to 
compare some of the recent data for the United States with those 
for normal conditions. 



SECTION I 
THE CORN PLANT 



CHAPTER II 
ORIGIN AND CLASSIFICATION 

In common with all living organisms, corn has been de- 
veloped through a long and slow evolutionary process. 
We can only guess at the probable place, origin, and course 
of evolution by a study of botanically related forms, and 
especially by a consideration of the embryonic develop- 
ment of the corn plant itself. How much of the evo- 
lutionary change was wrought by natural selection, and 
how much is the result of artificial selection, we can never 
know. It is probable that corn reached a stage of eco- 
nomic value before attracting the attention or care of 
man. Since then, no doubt most of the further changes 
are the result of natural variation and artificial selection. 

8. Geographical origin. — Numbers of investigators 
have made careful studies regarding the probable region 
in which Indian corn originated. In the early part of 
the nineteenth century, there was some controversy as to 
whether this plant was of American origin, the question 
being based on the contention of some persons that maize 
had been cultivated in Europe previous to the discovery 
of America. Careful investigation has not disclosed 
proof of this supposition, and it is not likely that a plant 
of such easy culture and obvious value could have existed 
in Europe without being known. According to Harsh- 
berger, it seems most probable that the cultivation of 
maize originated in the high plateau region of central or 

15 



16 COBN CB0P8 

southern Mexico at an elevation of about 4500 feet. 
In this region, plants of Zea canina are found growing wild ; 
it is also the native habitat of teosinte and gama grass, 
two plants closely related botanically to maize. Harsh- 
berger concludes that maize probably came into cultiva- 
tion in this region about the beginning of the Christian 
Era and spread rapidly both north and south, reaching 
the Rio Grande about 700 a.d., and the coast of Maine 
not later than the year 1000. 

When Columbus visited America in 1492, maize was in 
common cultivation. It was at once introduced into 
other parts of the world, reaching Europe, Africa, China, 
and Asia Minor early in the sixteenth century. Its early 
culture in the Eastern Hemisphere seems to have been 
confined mostly to the countries bordering on the Mediter- 
ranean Sea. 

Maize acquired many names in Europe, such as Spanish 
corn, Roman corn, Guinea corn, Turkish wheat, Egyptian 
corn ; these names probably indicate the places where its 
culture first became extensive. 

9. Biological origin. — The Gr amine se, or grass family, 
includes most of our common cereals, as maize, oats, 
wheat, and rye. A distinguishing feature of the tribe 
Maydece, to which maize belongs, is the separation of its 
staminate flowers (pollen-bearing) from its pistillate 
flowers (seed-bearing). Two grasses related to maize 
and of common occurrence in Mexico — the region in 
which corn is supposed to have originated — are gama 
grass (Tripsacum dactyloides) and teosinte (Euchlcena 
Mexicana) . 

Gama grass is distributed also over the southern half 
of the United States and usually is found on low, rich 
soil. At a distance a patch of this grass looks very much 




Fig. 3. — The relationship between gama, teosinte, and corn. 

1. Gama grass {Tripsacum dadyloides) . 2. Teosinte {Euchloena Mexicana). 

3. Corn (Zea mays). 4. Floral parts of gama grass: a, tassel; b, spike of tassei, 

bearing staminate flowers on upper part, and pistillate flowers on lower part; 

d, pistillate flower. 5. Floral parts of teosinte. 6. Floral parts. 



c, staminate flower 
of corn. 

C 



17 



18 CORN CROPS 

like maize. While it grows to a height of five to ten feet, 
the stem is slender and the leaf about half the width of 
the maize leaf. Thfe plant bears a tassel-like structure 
at the top and on the lateral branches, closely resem- 
bling the maize tassel, except that the seeds are borne 
on the lower part of each tassel and the pollen on the 
upper part. 

Teosinte, which is sometimes cultivated but does not 
mature north of Mexico, is more like maize than is gama 
grass, the plant being larger and the terminal tassel bear- 
ing pollen only. The lateral branches of the plant are so 
shortened that the terminal tassel-like structure is borne 
in a leaf axil, surrounded by a kind of husk as is an ear 
of maize, and bears only pistillate flowers, or seed. It is 
only a step in the production of an ear of maize, from 
teosinte, by a development of the central spike of the 
lateral tassel into an ear. 

It is probable that the early progenitor of maize was a 
grass-like plant having a tassel at the top and tassel-like 
structures on long, lateral branches, all tassels bearing 
perfect flowers. As evolution progressed, the terminal 
tassel came to produce only pollen, and the side branches 
only ovules, or seeds. Evolution often results in a greater 
'' division of labor," as in this case. At the same time, the 
lateral branches were shortened or telescoped into the 
leaf sheaths, these sheaths forming a covering, or husk, 
for the ear. Also it is probable that in this evolution the 
central spike of the tassel developed into an ear. 

The close relationship of maize and teosinte is proved 
by the crosses that have been made between the two. In 
the third or fourth generation after crossing, a peculiar 
type of corn is secured, identical with a type of maize that 
has been found growing wild in Mexico {Zea canina), and 



ORIGIN AND CLASSIFICATION 



19 




20 



CORN CROPS 



is supposed by some persons to be the true wild maize 
and the progenitor of our cutivated maize. 

Watson and Bailey both studied this wild maize and 
regarded it as a distinct species; however, since it has 
been produced by hybridizing te.osinte and maize, this 
probably accounts for its origin. 

CLASSIFICATION OF MAIZE IN GROUPS 

Order — Graminece 
Tribe — Maydece 
Genus — Zea 
Species — Mays 

10. Maize may be classified into the following groups, 
or " agricultural species " (after Sturtevant) : — 

1. Zea Mays canina (Watson), Maiz de Coyote. -Said to 
grow wild in Mexico, but the same type has been produced 
artificially by crossing teosinte and common maize. 
Characterized by a branching plant and by the production 

of numerous small ears in 
the leaf axils of lateral 
branches ; ears sometimes 
clustered; 4 to 8 rows on 
an ear, and ear 2 to 4 
inches in length. 

2. Zea Mays tunicata, the 
pod corns, Bui. TorreyBot. 
Club, 1904. 

Each kernel inclosed in 
a pod or husk and the ear 
inclosed in husks ; not com- 
as sweet, dent, flint, and 
Occasionally a few podded 




Fig. 5. — Pod corn. 

mon. All forms of kernel, 
others, are found in pod corn. 



kernels will occur on ears of ordinary corn. It has been 



ORIGIN AND CLASSIFICATION 



21 




Fig. 6. — Pop corn. 



supposed by some persons that pod corn represented 
a primitive or early type of corn, but there is no good 
evidence for this surmise. 

3. Zea Mays everta, the pop corns. 
Characterized by the excessive proportion of corneous 
endosperm and the small size of the kernels and ear. The 
popping quality is due to the explosion 
of contained moisture on the applica- 
tion of heat, and the best varieties 
for popping are usually corneous 
throughout. Two forms of seed are 
common, one of which is pointed at 
the top (rice pop corn) , and the other 
form is rounded (pearl pop corn), 
much as a small flint. All maize 
colors are found, as red, yellow, white, 
and blue. The ears are small but vary in length from 
2 inches in Tom Thumb to 5 inches for rice and 7 inches 

for some of the large pearl 
types. Rows vary from 
8 to 16. 

4. Zea Mays indurata, the 
flint corns. 

Characterized by white 
starchy endosperm, inclosed 
by flinty endosperm. Ker- 
nels oval in form ; in some 
varieties the corneous part is very thin at the top and a 
slight indentation appears. There are types of flint 
maize closely resembling pop corn on the one hand and 
approaching dent on the other, thus forming a series 
between the pop and dent corns. Flint maize has all the 
common maize colors. It varies in length of ear from 8 to 




Fig. 7. 



Flint corn. 



22 



CORN CROPS 



14 inches, and has 6 to 12 rows. The maize most com- 
monly cultivated by the early colonists and North 
American Indians is extensively cultivated at present in 
regions where the large dents 

mdo not mature. 
5. Zea Mays indentata, the 
dent corns. 
Characterized by horny endo- 
sperm at the sides, with starchy 
endosperm extending to the 
summit. By shrinkage of the 
starchy matter in drying, the 
summit of the kernel is drawn 



Fig. 8. — Dent corn. 



in and indented in various 
forms. The plant varies in 
height from 5 to 18 feet ; the ear varies in length from 
6 to 12 inches and has 8 to 24 rows. The most com- 
monly cultivated tjrpe in the United States. 

6. Zea Mays amylacea, the soft corns. 
Characterized by entire absence of corneous endosperm. 

All soft. No indentations, the kernel being shaped like 
that of flint corn. Ears 
mostly 8 to 12-rowed, 8 to 
10. inches in length. The 
usual colors occur. Culti- 
vated to some extent in 
Southwestern States, Mexico, 
and South America. 

7. Zea Mays saccharata, the 
sweet corns. 

Characterized by the translucent, horny appearance and 
more or less wrinkled condition of the kernel. Shrinking 
probably due to the conversion of starch into glucose. 




Soft corn. 



ORIGIN AND CLASSIFICATION 



23 



According to East, sweet corns are either dent or flint 
corns that have failed to convert their sugars into starch. 
Usual variations in color, size, 
and time of maturity. 

Zea Mays japonica. The 
leaves of this species are 
striped green and white ; the 
grain resembles a pop or small 
flint type. Cultivated as an 
ornamental. 

Zea Mays hirta. Character- 
ized by an unusual amount of 
hairs on leaves and sheath, 

sufficient to be distinctly noticeable. Flint, pop, and dent 
types. Found mostly in South America. 




Fig. 10. ■ — Sweet corn. 




Fig. 



11. — The six principal types of corn. From left to right, pod corn, 
pop corn, flint corn, dent corn, soft corn, and sweet corn. 



24 CORN CROPS 

Zea Mays curagua. Characterized by a serrate leaf 
edge. Probably a flint type. 

Chinese maize. A small-eared type resembling pearl 
pop corn, but characterized by a softer, opaque endo- 
sperm. Not starchy. A tendency for the upper leaves 
to be on one side of the plant. (See Bur. Plant Indus., 
Bui. 161.) 

Hermaphrodite forms (perfect flowers). A hermaphro- 
dite form has been described several times. Each pistil- 
late flower bears 3 stamens. The plant is usually short- 
jointed, with very broad leaves. (See Exp. Sta. Rec, 
Vol. 18, p. 732. Pop. Sci. Mo. Jan. 1906.; Oct. 1911.) 

References on early history : — 

Dakwin, Chas. (1874.) Animals and Plants under Domestica- 
tion, p. 338. 

De Candolle, A. (1882.) Origin of Cultivated Plants, p. 387. 

Sturtevant, E. L. (1899.) U. S. Dept. Agr., Office of Exp. Sta., 
Bui. 57. 

Harshberger, John W. (1893.) Maize: A Botanical and 
Economic Study. Bot. Lab. Univ. Penn., Vol. I, No. 2. 

Collins, G. N. (1909.) U. S. Dept. Agr., Bur. Plant Indus., 
Bui. 161. 

References on biological origin of maize : — 
Hackel. (1890.) True Grasses. Translated by Scribner and 

Southworth, pp. 36-43. 
Grasses of Iowa, Bui. Iowa Geol. Survey, 1903. 
Harshberger, J. W. Maize: A Botanical and Economic 

Study. Bot. Lab. Univ. Penn., Vol. I, No. 2, p. 94. 
Montgomery, E. G. (1906.) What is an Ear of Corn? Pop. 

Sci. Mo., Jan. 1906. Perfect Flowers in Maize. Same, Oct. 

1911. 

References on Zea canina : — 
Watson. Proc. Amer. Acad. Arts and Sci., 26 : 160. Grasses of 

Iowa. Bui. Iowa Geol. Survey, 1903: 11-19. 
Bailey, L. H. (1892.) Cornell Univ. Agr. Exp. Sta., Bui. 49. 



ORIGIN AND CLASSIFICATION 25 

References to crosses of maize and teosinte : — 
Harshberger, J. W. Crosses of Teosinte and Maize. Garden 

and Forest, IX : 522. 
U. S. Dept. Agr. Year Book, 1909 : 312. 

References on classification of maize : — 
BoNAFAus. Mais, folio. Paris, 1836 (folio). 
Index Kewensis. 

Sturtevant, E. L. (1899.) Varieties of Corn. Bui. 57, OfBce 
of Exp. Sta., U. S. Dept. Agr. 



CHAPTER III 
DESCRIPTION OF THE CORN PLANT 

Under the head ^'Biological Origin" (page 15) it is 
seen that corn, through a process of evolution, probably 
came from some branched, grass-like plant resembling 
teosinte. In Fig. 13 is shown a drawing of a corn plant, 
with leaves removed, illustrating the grass-like character. 

The main stem is divided by nodes. Below the ground, 
the nodes are very close together and give rise to roots ; 
at the surface they give rise to branches or tillers and 
also roots, and above ground to leaves and ears. 

The branches or tillers correspond in detail to the main 
stem, having in all cases as many nodes and leaves as the 
main stem above the point of attachment. The ear is 
only a modified branch, as the ear stem has exactly the 
same number of nodes as the main stem above, and the ear 
corresponds in many details to the tassel. 

11. The root. — When a kernel of maize germinates there 
is produced, first, a root from the tip end of the seed. A 
few hours later the stem will appear at the upper end of 
the germ chit. At nearly the same time two to three roots 
will be sprouting from about the median point between 
root and stem. These are the " temporary " roots and 
maintain the plant for only a short time. When the corn 
plant is about six to ten days old, whorls of permanent roots 
begin to develop at a point about one inch below the ground 
surface. The seed may be planted 1 to 5 inches deep, 

26 



DESCRIPTION OF THE CORN PLANT 



27 




Fig. 12. — Corn roots. 1. Ordinary distribution of roots when corn is 
"planted in rows three feet six inches apart in a deep loam soil. Figures 
in margin indicate feet. In a hardpan soil roots do not penetrate so 
deep. 2. Single lateral root. 3. Small branch root showing root- 
hairs. 4. Root and root-hairs enlarged. 5. Cross-section of 4 at 
point a. 7. Root-hair in contact with soil grains. 



28 COBN CROPS 

but the permanent roots develop at about the same dis« 
tance below the surface. 

12. The spread of the roots. — Root studies on maize 
at the Wisconsin, Minnesota, Colorado, New York, and 
North Dakota experiment stations indicate that the 
permanent roots first spread laterally for about nine to 
twelve days, when they will have reached a distance 16 
to 18 inches from the plant and will be confined mostly 
to a zone between 3 and 6 inches below the surface. Frx)m 
this time on, the root system rapidly extends downward 
as well as laterally, at eighteen days reaching a depth of 
about 12 inches and at twenty-seven days a depth of 18 
inches, with a lateral extension of 24 inches. By the time 
the maize plants are two months old, when they are 5 to 
6 feet high and coming in tassel, the lateral spread of roots 
has a radius of about 4 feet and penetrates the soil to a 
depth of 3 to 4 feet. The number of roots continues to 
increase until the plant is mature, when they fully occupy 
the upper 3 to 4 feet of soil. 

The depth to which roots may penetrate is somewhat 
dependent on the character of the soil, as is shown by the 
Colorado station. In a black adobe soil, the roots were 
limited mostly to the upper 12 inches, while on another 
heavy soil containing much clay they penetrated only 24 
inches. 

13. Distance from surface. — At a distance of 6 inches 
from the plant the upper roots are usually about 3 inches 
below the surface, sloping gently to 4 or 5 inches deep at a 
distance of 2 feet from the plant. However, when there is 
abundance of moisture in the surface, feeders may come 
within 2 inches or less. Distance from the surface seems 
to be controlled by the presence of sufficient moisture, and 
also by the degree of shading, since roots are very sensitive 



DESCRIPTION OF THE CORN PLANT 29 

to light. Late in the season, when the soil is well shaded, 
roots will be found very near the surface ; but ordinarily, 
during the growing season, they are 3 to 4 inches below. 
The method of planting may also exercise some influence 
on the depth of upper roots. At the Kansas station, ^ 
where the root systems of " hsted " corn were compared 
with those of surface-planted, the upper roots of the 
former were found to average about 1 inch deeper during 
the cultivating season, especially near the plant, thus 
permitting deeper cultivation. 

14. Types of roots. — • Maize roots may be classed as 
primary roots, brace roots, lateral roots, and hair roots. 
The main roots are those having their origin at the base 
of the stem; they are twenty to thirty in number and 
4 to 6 feet in length. The lateral roots are numerous small 
roots thrown off from these, and they again may produce 
other laterals. Their number is very large and may aver- 
age several hundred to each main root; in length they 
vary from less than 1 inch to 1 or 2 feet. The root-hairs 
are microscopic in size, single-celled, and infinite in number. 
They are borne on the main roots in their earlier growth, 
and on all the laterals. Root-hairs are short-Hved and 
limited to the newer root growth, or rather to a zone near 
the growing point of the roots. They are absorbent or- 
gans, and do not grow to be roots. 

15. The proportion of root. — The total weight of the 
root in a corn plant has been found to be about 12 to 15 
per cent of the weight of the total plant, including the 
ear .2 The total length of roots laid end to end, of a single 
plant of small grain, as wheat or oats, has been estimated 
at 1600 feet ; but in a corn plant it would be greater. 

1 Kan. Agr. Exp. Sta., Bui. 127:203. 

2 KiESSELBACH. Nebr. Agr. Exp. Sta., Rpt. 1910 : 131. 



30 CORN CROPS 

16. The amount of root. — The amount of root devel- 
oped is more or less in response to the needs of the plant. 
When moisture is abundant or excessive, the plant will not 
develop so much root as when the moisture content is 
normal or below normal. Also in very dry soil, with a 
moisture content below the wilting point of plants (about 
12 per cent in loam soils), the growth of roots is limited, 
as is also the case when the soil is very hard. 

17. Functions of the root. — The root functions may be 
stated as : (1) the absorption of water and of salts in solu- 
tion; (2) the excretion of organic substances, especially 
carbon dioxid, and possibly free organic acid, also mineral 
salts and the salts of organic acids ; (3) the solvent effect 
of the excretions on soil particles. 

The absorption of water and solutions, as well as the 
exudations, take place largely through the root-hairs. 
These root-hairs are constantly produced from the epider- 
mal cells near the growing root tip. They are forced into 
close contact with the soil grains ; in fact, the soil grains 
are more or less embedded in the root-hair tissues. Each 
soil grain in a moist soil is surrounded by a film of water 
containing more or less mineral matter dissolved from the 
soil. This soil water is absorbed by the root-hair, and it 
seems probable that exudations from the root-hair also aid 
in freeing less soluble minerals in the soil grains. The 
process of absorption is by means of osmosis.^ 

1 Osmosis. — When two solutions of different density are separated by 
a porous membrane, there will be first a movement of the weaker solu- 
tion through the membrane into the stronger, and later a return move- 
ment, the process continuing until the two solutions have the same den- 
sity. The contents of a root-hair being denser than the soil solution 
surrounding it, there is a constant movement of the soil solution into the 
root-hair. By some means the exosmosis, which would take place in the 
case of an ordinary membrane (movement of the cell solution outward), 
seems to be restrained in the root-hair, probably by some functional 



DESCRIPTION OF THE CORN PLANT 31 

18. The stem. — The stem of maize differs from that of 
other cereals in the fact that it is solid — filled with pith — 
while others are hollow. The maize stem may vary in 
height from 2 feet, in the case of dwarf pop corn, to 18 or 
20 feet in some of the tall southern varieties. 

The nodes not only serve to strengthen the stem, but 
are also the points of origin for all its lateral outgrowths, 
as roots, branches (tillers), leaves, and ears. 

The stem usually extends not more than three to five 
inches below the ground surface. This part is divided 
into about six to ten short nodes, each bearing a whorl 
of roots. Above the soil surface each node bears a leaf 
and in addition either a branch or an embryonic ear. The 
early northern varieties of maize, with a height of about 
6 feet, usually have about eight to ten nodes above the 
soil, while the tall southern varieties may have eighteen 
to twenty. A typical plant in Illinois or Indiana will 
have about fourteen nodes, with one or two branches from 
the surface nodes and an embryonic ear at each node ; 
usually, however, only the ear at about the eighth node 
develops, the others remaining dormant. 

In Fig. 13 is shown a stem from a plant about 10 inches 
high. The full number of nodes, and also of leaves, is 
formed. Growth of the stem from this point on will be by 
a lengthening of the internodes, but there will be no in- 
crease in number of nodes. This is called internodal 
growth, in distinction from the apical, or terminal, growth 
of many other plants — as peas and beans, where new 
growth is- constantly taking place at the apex. 

The outer part of the stem is a thin shell of hard tissue, 

activity of the cell. The result is a much greater movement into the 
root-hair than exudation out of it. The soil solution passes from the 
root-hair into the root and is finally transmitted to the stem and leaves. 



32 



CORN CROPS 



the function of which is to give strength and rigidity. A 
cross-section of the stem will show, in addition to the pith, 




Fig. 13. — Development of the corn stem. 
1. Plant about 10 inches high. 2. Section of 
1, at base, showing that all nodes, leaves, and 
tassel are more or less developed at this stage ; 
growth is internodal. 3. FuU-grown stem 
with leaves removed. 4. Cross-section of 
stem. 



a large number of fibrous strands, 
known technically as fibro-vascular bun- 
dles. It is through these bundles that 
the water taken in by the roots passes 
up the stem and is distributed through- 
out the plant; and again, when the 
leaves have elaborated plant-food from 
the material taken up from the soil and 
out of the air, this plant-food is carried 
down these same fibro-vascular bundles and distributed 
to those parts where it is needed, as the growing ear or 
the roots. 



DESCRIPTION OF THE COBN PLANT 33 

19. Tillers. — If a young corn plant about 8 inches high 
is carefully dissected, two or more small buds will be noted 
in the axils of the first leaves. If conditions are favorable, 
one or more of these buds will develop into a branch of 
the plant, or a '^ tiller." If conditions are unfavorable, 
as in poor soil, or when the plants are close, the buds may 
remain suppressed and never grow. On a cold clay or wet 
soil very few of the tillers develop ; while on a warm, sandy 
soil, especially if fertile, every plant may develop one to 
three or four tillers. A good example of this is the very 
abundant tillering common in cornfields in the light but 
fertile soils on the west edge of the corn-belt (central 
Nebraska) ; while the same varieties on the heavier clay 
soils of Ohio or New York will rarely develop tillers. 
Every corn plant has several latent buds, which may 
develop if conditions are favorable, but which otherwise 
may remain dormant. The tiller may develop its own 
root system and ears, and may function in all respects as a 
normal plant. A tendency to tiller, however, is somewhat 
hereditary, as certain small varieties of flint and sweet 
corn normally produce well-developed ear-bearing tillers, 
while some of the large dent varieties seldom tiller. 

20. Leaves. — If a small corn plant a few days old be 
taken and a cross-section made just above the first node, 
the full number of leaves may be identified, wrapped into 
a kind of stem (Fig. 13). As the stem elongates the 
leaves are gradually exposed, but the leaf growth takes 
place mostly while the leaves are yet enfolded. There is 
very little increase in size after 'the leaf is fully exposed. 

The structure of a leaf is more complicated than appears 
from a casual examination, because of its many functions. 
The functions are principally : (1) to provide for the free 
circulation of solutions and air throughout the leaf ; (2) to 



34 



CORN CROPS 



give off constantly large quantities of excessive water 
taken up by the roots ; (3) to elaborate plant-food from 
the minerals and water taken out of the soil, combined 
with carbon and oxygen taken from the air ; (4) to ab- 
sorb energy from the sun which is necessary in order that 



Midrib 



Ligule 




Mesophy/I 
tissue ^ 



Fig. 14. — Leaf structure. The movement of water and solutions takes 
place through the fibro-vascular bundles. The mesophyll tissue fur- 
nishes the means for elaborating plant-food from raw material. Inter- 
change of air and gases takes place through the stomata. The bulli- 
f orm cells are similar to mesophyll cells, but contain a large percentage 
of water. Shrinkage of these cells causes the leaf to roll in dry weather. 



these activities may proceed. Each of the above functions 
of the leaf requires specialized tissues which are briefly de- 
scribed as follows (21, 22) : — 

21. The vascular system. — If a maize leaf is examined, 
there will be found running lengthwise a large number of 



DESCRIPTION OF THE CORN PLANT 



35 



parallel veins. On examining a cross-section of the leaf 
under the microscope, each vein will be seen to contain a 
fibrous bundle of various kinds of tissues, known as a 
fibro-vascular bundle. In Fig. 14 are shown some of these 
large, thick-walled cells, resembling somewhat the veins of 
an animal ; and it is by means of these that solutions are 
circulated through the leaf. These fibrous bundles ex- 
tend into the stem and the roots, making a direct passage 
for the transfer of soil solutions taken up by the roots 
through the stem and out into the leaves. 

22. Air passages. — ^Throughout the leaf tissues are 
systems of air passages. These are connected with small 
openings of the leaf surface, or stomata. Fresh air is con- 
stantly coming into the leaf through these stomata, car- 
rying carbon dioxid and oxygen, both of which are utilized 
by the plant in connection with the minerals taken up from 
the soil and elaborated into plant-food. 

23. Loss of water. — As the air passes out of a leaf it 
constantly carries out the water that has been taken up 
from the earth. The outer covering, or epidermis, of the 
leaf is impervious to water or air, but there are stomata 
at regular intervals. The number of these is very great, 



Kind op Leap 


Number of Stomata in 
One Square Inch 




Upper Side 


Under Side 


Indian corn {Zea Mays) 

Sunflower (Helianthus annuus) 

Red clover {Trifolium pratense) . . .' 

Hop {Humulus hwpulus) 

Apple (Pyrus Malus) 

Pea {Pisum sativum) 


60,630 

112,875 

113,515 





65,145 


101,910 
209,625 
216,075 
165,120 
156,670 
139,320 



36 COBN CBOPS 

usually being most numerous on the under side. The 
above table gives the number estimated for several 
kinds of leaves. ^ 

The stomata also close more or less when the leaves begin 
to wilt, thus preventing to some extent the loss of moisture. 

24. Chlorophyll-bearing cells. — The work done by the 
leaf involves the expenditure of energy. There are a large 
number of cells in the maize leaf filled with minute green 
bodies, called chlorophyll grains. These not only give the 
green color, but arrest the energy of the sun's rays, making 
use of this energy to perform the various activities of the 
plant. 

25. The flower. — The male, or staminate, flowers are 
borne in the tassel. The anthers are three in number and 
filled with pollen. While the pollen sacs are small, about 
one-fourth inch in length, yet each is estimated to contain 
2500 pollen grains. 

The female, or pistillate, flowers are borne on the ear 
and are closely related in structure to the male flowers. 
When very young, they are borne in pairs, but one is very 
small and seldom develops. Occasionally both of these 
grains develop in the tassel flowers of pod corns. Sturte- 
vant 2 mentions also an ear of podded flint corn from Ohio, 
in which the kernels were twinned. These reversions in- 
dicate that at some time in the early evolution of maize 
both these flowers functioned, but for some reason only 
one now develops. 

The principal parts of the pistillate flower are an ovary, 
or egg cell, a carpel which surrounds this for protection, 
and a long extension of the carpel, called the style, or 
^' silk." The details of fertilization are given later. 

iBessey, C. E. Botany (Briefer Course), p. 45. 
2 Bui. Torrey Bot. Club, 1894:336. 



DESCRIPTION OF THE CORN PLANT 37 

26. The ear. — The probable origin of corn from some 
grass-like plant similar to teosinte is discussed under 
Biological Origin (p. 15). 

The ear may be regarded as a branch of the main stem, 
the ear stem having exactly as many nodes as the main 
stem above the ear, the husks corresponding to the leaf 
sheaths and the ear to the tassel; the side branches, 
however, are no longer present, while the central spike 
has been enlarged into a cob, and the pistillate flowers, or 
grains on the ear, correspond to the pollen flowers.^ 

The ear is the storehouse of the maize plant, whfere is 
produced not only the young germ, but also a store of 
starch, protein, oil, and other products for its future 
nourishment, much as a swarm of bees makes a store of 
honey for the young, laying eggs in the cells at the same 
time. As mentioned heretofore, these products are first 
prepared by the leaves and later transmitted to the ear. 

References on distribution of maize roots : — 
Pammel, L. H. Grasses of Iowa. Iowa Agr. Exp. Sta., Bui. 

54 : 8-13. 
King, F. H. Wis. Agr. Exp. Sta., Rpt. 1892 : 112; and 1893: 

160. 
Hays, W. M. (1889.) Minn. Agr. Exp. Sta., Bui. 5. 
Ten Eyck, A. M. (1899-90.) N. Dak. Agr. Exp. Sta., BuL 

36: 43. 
Shepperd, J. H. (1905.) N. Dak. Agr. Exp. Sta., Bui. 64. 
Ten Eyck, A. M. (1904.) Kan. Agr. Exp. Sta., Bui. 127. 
Colo. Agr. Exp. Sta., Rpt. 1896: 181. 
N. Y. Agr. Exp. Sta., Rpt. 1888: 171. 

References on tillering of maize : — 
Neb. Agr. Exp. Sta., Bui. 91 : 16. 
Pop. Sci. Mo., Jan. 1906:55. 

1 What is an Ear of Corn ? Pop. Sci. Mo., Jan. 1906. 



CHAPTER IV 
^ PHYSIOLOGY OF CORN PLANT 

Plant physiology deals with the activities and functions 
of the physical parts of the plant. Not all parts of a 
plant have a present important function. Certain parts 
may be regarded as rudiments left in the process of evo- 
lutionary change, and they may even be detrimental. In 
other cases, certain parts may be regarded as only chance 
variations of no value from an economic view point. It 
is therefore important to make a careful analysis of plants, 
to determine the function of each part, which parts have 
an important function, and how the proper activities of 
the plant are favored or hindered. 

27. Living plants. — One of the distinctive characters of 
living plants as compared with dead material is the fact 
that many forces of nature may act as a '' stimulus " and 
get a response entirely at variance with the usual result. 
This is well stated in Strasburger ^ as follows : — 

"The free end of a horizontally extended flexible rod bends 
downwards merely by its own weight. The same result will 
follow if any part of a dead plant, such as a dry stem, be substi- 
tuted for the rod. But if a Uving, growing stem be used in the 
experiment, then the action of gravity will manifest itself in a 
manner altogether at variance with its ordinary operation. 
That part of the stem which is still in a state of growth will 
ultimately curve upwards, and by its own activity assume an up- 

1 Strasburger, Noll, Schenk, and Karsten. (1908.) Textbook 
of Botany, p. 173. 

38 



PHYSIOLOGY OF CORN PLANT 39 

right position; it moves in a direction exactly opposite to the 
attractive force of gravity. If a tap-root be similarly experi- 
mented upon, it will, on the contrary, continue its downward 
movement until it places itself in a line with the direction of 
the attraction; a rhizome, however, under like circumstances, 
would constantly maintain its growing apex in a horizontal 
position. In these three experiments, the force of gravity is 
exerted upon horizontal portions of plants. The physical condi- 
tions are the same in each case, yet how entirely different the 
results." 

The above phenomena are some of the manifestations of 
" life." In the same way, light, heat, moisture, and 
other physical factors will act as a '^ stimulus " to living 
plants, but the response is not always what would be ob- 
tained with dead material, and it may be the opposite. 
This fact should be kept in mind in dealing with living 
plants. 

28. Stability of the plant. — A corn plant one inch in 
diameter at the base may be 100 to 125 inches in height, 
yet it will have a broad spread of leaf, bear a heavy ear, 
and be able to maintain itself without breaking or falling 
prostrate in a heavy wind.- A rye plant bearing a heavy 
head may be five hundred times as tall as the diameter of 
its base. This rigidity of the plant body is necessary in 
order that it may reach considerable height and expand its 
leaves to light and air. Rigidity is due principally to 
turgidity in the soft tissue or young plant, and to the 
mechanical tissues in the older and stronger parts. 

29. Turgidity. — In the leaves of a corn plant is a 
certain set of cells, known as bulliform cells. These are 
located near the upper surface between the ribs, or veins. 
(See Fig. 14.) When moisture is abundant, these cells 
absorb water until they are turgid. The leaf is then 
spread out flat and is more or less rigid and brittle. How- 



40 CORN CROPS 

ever, when the weather is very hot or when soil moisture 
is low, the cells lose water enough so they are no longer 
turgid, and the leaf then becomes limp and rolls up. In 
the same way, all cells of the plant may be more or less 
turgid, aiding in giving rigidity to the plant body. 

30. Tension. — If a section a few inches long of the 
stem of green corn be taken and the outer peripheral tissue 
be removed from the pith, the pith will at once expand in 
length and some force will be required to restore it to 
normal length. It will thus be seen that there is a natu- 
ral tension at all times between the outer cortex and the 
pith. This tension adds to the rigidity of the stem. 

31. Mechanical tissue. — The supporting framework 
is made up of woody and fibrous tissues in the outer part 

and the nodes of the stem and in the 
midribs and veins of the leaves. These 
are mostly comprised of fibers (scleren- 
chyma or bast) of great tensile strength. 
Quoting from Strasburger, " the sus- 
taining strength of sclerenchymatous 
fibers is, within the limits of their elas- 
FiG. 15. — Illustrat- HQUy jn general equal to the best 

mg resistance to , . 

bending when the wrought iron, or hammered steel, 
supporting tissue is T^g fibers are bound together, giving 

on the outside of ^ i , • i i 

the stem, as in corn, a strong elastic body. 

One side must be The location of the framework on the 

shortened and the , . , ,, ,, • ,■, , e 

other stretched. outside, rather than m the center, oi 
the stem adds to the rigidity. For 
example, if an elastic rod be bent (Fig. 15), the inner side 
is shortened and the outer lengthened. If a supporting 
skeleton be placed in the center of this rod, then the rod 
is flexible and considerable bending would be possible 
without much resistance from the center ; but if the sup- 




PHYSIOLOGY OF CORN PLANT 



41 



Composition of Corn Plants 



Green plants, six 
weeks old 



Green plants, ears 
jiist glazed 



Mature plants 



Water 
90% 



Water 

80% 



Water 
60% 




Composition of Dry Matter. Percentage Basis 




Green plants 
six weeks old 

Green plants 
ears just glazed 

Mature plants 



Fig. 16. — Composition of corn plants at three stages of growth. The 
upper figure shows a progressive increase in percentage of dry matter 
as the plant approaches maturity. The lower figure shows the pro- 
gressive change in character of dry matter. 



42 



CORN CROPS 



porting skeleton be on the outside, then much greater 
resistance is offered. 

In the root, however, the mechanical tissue is in the 
center, thus allowing the root to bend easily about among 
obstructions and at the same time giving pulling strength. 

32. Nutrition. — Probably the most interesting, as 
well as the most important, knowledge regarding the corn 
plant is the method by which its supply of elements for 
growth is secured from the soil and air, and the factors 
affecting the assimilation and use of such plant-food. 



THE COMPOSITION OF A CORN PLANT 

33. If a green corn plant 2 or 3 feet in height be dried 
in an oven until all the water has been driven out, it will 
be found that about 90 per cent of the total weight is 
water and only 10 per cent is solid, or dry matter. When 
in the roasting-ear stage, the plants are about 80 per cent 
water, and later, at maturity, 60 per cent. 

TABLE IX . 

Average Composition of Green Maize ^ 



Constituent 


COMPOSITION 

OF Fresh 
Plants 


Composition of Dry Matter at 
Three Stages 


Six Weeks 
Per Cent 


Ears just 
Glazed 


Mature 
Plant 


Water .... 
Ash 


79.0 
1.2 
1.7 
5.6 

12.0 
.5 


17 
27 
17 

35 
15 


10 
14 

22 

50 
4 


6 


Protein 

Fiber 

Nitrogen 

tract 
Fat 


free ex- 


9 
25 

57 
3 







1 From Jenkins and Winton, OflEice of Exp. Sta. 
Bui. 11. 1892. 



U. S. Dept. Agr. 



PHYSIOLOGY OF CORN PLANT 



43 




-'iV'ash from $o\i \%greeh wTt''-\S: 

Fig. 17. — The source of elements supplying a maize plant. About 10 
per cent of the green weight (50 per cent of dry weight) is carbon. 
About 5 per cent is oxygen and 4 per cent hydrogen. The oxygen is 
derived from the air in combination with carbon, from water or from 
oxide salts. The hydrogen comes principally from water. Ash from 
the soil equals about 1 per cent, and nitrogen | per cent of the green 
weight. About 80 per cent of the green weight is water, not in com- 
position. 



44 COnN CROPS 

The dry substance is combustible, and when it is ignited, 
about 90 to 95 per cent will be consumed, leaving a residue 
of ash. The combustible part consists principally of the 
elements carbon, hydrogen, and oxygen, with a smaller 
quantity of nitrogen. The ash left is made up of mineral 
substances taken from the soil. Thus, only about one 
per cent of the weight of a green plant comes from the soil. 

34. The essential constituents. — There are ten essen- 
tial elements necessary to plants, one of these coming from 
the air, two from water, and six from the soil, while one 
— nitrogen — comes indirectly from the air through the 
soil. Carbon comes only from the carbonic acid gas of the 
atmosphere, hydrogen and oxygen from water (oxygen also 
from the air, and oxid salts), nitrogen from the soils, as 
nitrates or ammonium salts. The other six essentials, 
namely, sulfur, phosphorus, potassium, calcium, mag- 
nesium, and iron, are taken from the soil. 

Plants do not find these elments in simple forms, but in com- 
bination — for example, the hydrogen and oxygen from water, 
where it is in combination ^s H2O, and carbon from carbon 
dioxid (CO2). All the minerals, as phosphate, potassium, and 
the others, are always found in combination. A demonstra- 
tion of how plants can live on these minerals when in solution 
may be made by taking piu-e distilled water and dissolving the 
following mineral salts (after V. D. Crone) : — , 

Distilled water ... ,..„<, o „.. . 1-2 liters 

Potassium nitrate .o. o o .= .„„„.. 1.0 gram 

Ferrous phosphate « = » » „ » , , . . . . 0.5 gram 

Calcium sulfate . <. . . . , o 0.25 gram 

Magnesium sulfate 0.25 gram 

If properly handled, a corn plant may be grown to maturity 
in this solution. 

In addition to the "essential" elements found in the ash of 
plants there are also other elements, as sodium and silicon, 



PHYSIOLOGY OF CORN PLANT 45 

found in large quantities ; but these are probably not essentia] 
to growth. 

THE ABSORPTION OF WATER 

35. It has been pointed out in the text that the water 
absorbed by plants is a dilute solution of all the soluble 
substances in the soil, the absorption taking place through 
the vast number of root-hairs, from which the water solu- 
tion passes into the lateral roots, up the stem, and out 
into the leaves. The water passes up the fibrous bundles 
found all through the pith. This can be demonstrated 
by cutting off a stem near the ground early in the morn- 
ing, when root-pressure is high. Water will soon exude 
in small drops wherever the fibro-vascular bundles are cut. 
During the heat of the day, root-pressure is negative, and 
no result can be secured. 

THE GIVING OFF OF WATER 

36. Water loss ^ from the plant serves several functions, 
the most important of which is the concentration of the 
water solution. By constant evaporation of water the 
salts taken up in solution are left in the plant, to be 
utilized in its growth. • The leaf is so constructed as to 
facilitate the giving off of quantities of water and at the 
same time protect the inner tissues. 

The leaf is covered with a strong epidermis, which has, 
however, an enormous number of stomata. The number 
in a single corn leaf of average size is estimated at sixteen 
to twenty millions. These small openings are connected 

1 Water loss from the plant is of two kinds, namely, transpiration and 
evaporation. The former is closely associated with assimilation, and the 
amount of water given off as a result of this process is comparatively 
small. The greatest loss is by simple evaporation, in common with all 
objects exposed to dry air. 



46 



CORN CROPS 



with a series of air spaces in the leaf so that there is free 
movement of air into and out from the leaf. Also, the 
vascular bundles, which deliver the water from the roots 
into the leaf, are spread out in the leaf into a fine net- 
work so that every part is quickly supplied with water as 
it evaporates. 

The quantity of water evaporated from day to day 
depends directly on the conditions of climate and on the 
amount of leaf area exposed. An average corn plant has 
about 8 square feet of leaf surface, while a full stand of 
corn has a total leaf area equal to twice the area of land 
on which the corn is growing ; in other words an acre of 
land would have about two acres of leaf surface. The 
daily water loss. per plant varies from 3 to 10 pounds, 
depending on the humidity of the air and on the wind, 
just as does any other object or a free water surface. The 
following data, taken at the Nebraska Experiment Station, 
illustrate the above statements : — 

TABLE X 

Daily Variation in Water Loss from Plants and Free 

Water ^ 



Interval of 24 Hours, ending 

AT 7 P.M. 


Water Loss per 
Plant 
Grams 


Water Loss from 

Free Water 

Grams 


July 27, 1911 .... 


4550 


454 


July 28, 1911 








2333 


372 


July 29, 1911 








1579 


173 


July 30, 1911 








2802 


232 


July 31, 1911 








3561 


314 


August 1, 1911 








3982 


374 


August 2, 1911 








3419 


311 


August 3, 1911 








2143 


204 



1 Nebr. Agr. Exp. Sta., 24tli Ann. Rpt., p. 102. 1911. 



PHYSIOLOGY OF CORN PLANT 47 

ASSIMILATION 

37. The taking up of carbon from air and uniting it 
with other elements to form plant tissues is called assim- 
ilation. Carbon is found in nature, as coal or graphite, 
or it is artificially prepared from wood, as charcoal. 
Carbon is the most important constituent of all plants, 
composing about 50 per cent of the dry weight. 

Carbon can be demonstrated by charring, that is, by burning 
a piece of maize stem without sufficient air for complete com- 
bustion, when other substances will be driven off by the heat, 
leaving the carbon. So much carbon is present that the stem 
will retain its shape and structure. 

When any substance is burned or decomposes, the 
carbon present passes into the air as carbon dioxid (CO2) . 
This gas constitutes about 0.03 per cent of the atmos- 
phere. 

A maize plant takes air into the leaves through the air 
pores (stomata) and extracts the carbon dioxid. The 
air then passes out again, carrying water and by-products 
— often oxygen — of which the plant should rid itself. 

38. The necessary energy for maintaining the activities 
of the leaf is derived from the sunlight. Some of the 
leaf cells contain small green chlorophyll bodies. When 
the plant is in strong sunlight, these chlorophyll bodies 
rapidly accumulate starch grains. If the plant is placed 
in darkness, however, no starch will be made. 

In the same way, we may show the necessity of carbon dioxid, 
by placing growing plants in air artificially freed of this gas. 
Even in the presence of bright sunshine, no starch will be accu- 
mulated. 

39. The by-product of assimilation is pure oxygen. The 
chemical process of the manufacture of starch from carbon 
dioxide and water, through the activities of chloroplasts, 



48 CORN CROPS 

may be illustrated as follows, leaving out intermediate 
steps : — 

6 CO2 + 6 H2O = CeHiaOe + 6 O2 

(glucose + oxygen) 
C6H12O6 = CeHioOs + H2O 
(starch + water) 

While the starch is made in the leaves it cannot be dis- 
tributed in this form to other parts of the plant, as starch 
is insoluble. It is therefore first converted into sugar 
and in this form is distributed to the stem, roots, ear, or 
wherever needed for growth. The juice of a green maize 
stem may contain 10 per cent or more of sugar during the 
earing season, when it is being transported from leaves to 
stem and ear. This soluable sugar may be converted 
into many forms of carbohydrate material, as fiber or 
starch. In the ear it is principally deposited again as 
starch. 

40. Growth. — Following the plan outlined by Sachs, 
the growth of a maize plant may be divided into three 
distinct phases, as : — 

1. The early growth period (embryonic), in which the 
rudiments of new organs are formed. 

2. Elongation of the already formed embryonal organs. 

3. Period of internal development. 

The first period covers about the first three weeks of 
growth. A plant three weeks old will have all parts, as 
the full number of leaves and nodes, most of the main 
roots, and embryonic tassel, ears, and tillers. From this 
time on, growth consists principally of the elongation 
and development of these parts. Later there is a third 
phase, that of internal development, as the depositing 
of starch in the ear and the strengthening of fibrous 
tissues. 



PHYSIOLOGY OF CORN PLANT 49 



REPRODUCTION 



41. In maize, as in most plants, nature has provided 
for the perpetuation of the race through the abundant 
production of seeds. An average maize plant produces 




Fig. 18. — An ear of corn in full silk, just ready for pollination. 
E 



50 



CORN CROPS 



about 1000 seeds, usually all on one ear ; in some varieties, 
however, two or more ears are produced. 

42. Pollen. — The pollen, or fertihzing element, is pro- 
duced in the tassels and usuallj^ begins falling one to two 
days before silking; there is great irregularity in this 




Fig. 19. — The process of fertilization of the corn flower. Each embryonic 
grain produces a long style or " silk." Each silk must receive one or 
more poUen grains. 



PHYSIOLOGY OF CORN PLANT 51 

respect, however, some plants producing silk before 
pollen. 

43. Style. — • Each grain produces a style, or silk. The 
grains about one-fourth of the way from the base of the 
ear silk first, and the process passes gradually toward the 
tip, the entire period of silking requiring two to four days. 




Fig. 20. — Young corn kernels and silks. 



52 



CORN CROPS 




44. Fertilization. — For fer- 
tilization to take place, every 
silk must receive at least one 
pollen-grain, and fertilization 
is probably surer if it receives 
several. As the pollen is dis- 
tributed by wind, it must be 
very abundant to insure pol- 
lination ; therefore, ten to 
twenty thousand pollen grains 
are produced to every ovary, 
or embryonic kernel. 

The exposed end of the silk, 
or style, is covered with fine 
hairs and is also adhesive, so 
that pollen-grains readily ad- 
here when they come in con- 
tact. It is not necessary for 
the pollen to fall on a particu- 
lar part of the silk; it may 
reach any of the exposed sur- 
face. In fact, fertilization has 
been accomplished by placing 
the pollen on the silk within 
the husk. 

Soon after a pollen-grain 
falls on a receptive silk it 
sends out a tube, or filament. 

Fig. 21. — Ear of corn showing zone 
poorly fertilized. The ear silks in 
successive zones from near the butt 
toward the tip. Some unfavorable 
condition happened when this zone 
was in silk. 



PHYSIOLOGY OF CORN PLANT 53 

which penetrates the silk ; and soon the contents of the 
pollen-grain pass down to the egg, in the embryonic seed 
at the base of the silk. Immediately upon fertilization, 
the ovule begins a rapid growth. In case a part of the 
silk should fail to receive pollen, those ovaries will not 
develop, and the result will be irregular rows on the ear. 
Sometimes in very hot and dry weather the pollen is 
killed and will not fertilize. Also, insects such as grass- 
hoppers often eat off the silks, or a part of them, thus 
preventing fertilization. 

Several investigators have studied fertilization and embryonic 
development of the corn ovule, as Guignard, Webber, True, and 
Poindexter. No one has reported observing the passage of a 
pollen-tube down the silk. There is some question as to whether 
the pollen-tube actually passes down within the tissues of the 
style, or whether it may not follow the slight depression or 
groove on one side of the style. Guignard calls the opening near 
+he base of the style the " stylar canal," and thinks that the pol- 
len-tube enters this opening, but he did not observe it. When 
the ovule is finally reached, it has not been definitely observed 
at just what point the pollen-tube enters. 

True, Rodney. Bot. Gaz. 18 : 215. 

Poindexter, C. C. The Development of the Spikelet and Grain of 
Corn. The Ohio Nat., Vol. IV, No. 1, Nov. 1903. 



SECTION II 

PRODUCTION AS RELATED TO CLIMATE 
AND SOILS 



CHAPTER V 
RELATION OF CLIMATIC FACTORS TO GROWTH 

The ability of corn to yield is indicated by certain max- 
imum yields that have been obtained under favorable 
conditions. Edward Enfield/ in 1866, listed a number of 
record yields which had been published between 1840 
and 1866. 

45. The average of fourteen record yields collected from 
seven States was 145 bushels per acre, two of these records 
being 200 bushels per acre. The American Agriculturist ^ 
records in 1857 a yield of 857 J bushels on 5 acres, or an 
average yield of 17 IJ bushels per acre. Hartley^ reports 
a 90-acre field of corn in Pennsylvania averaging 130 
bushels per acre, the same farmer having averaged 100 
bushels per acre for twelve years. The four largest 
yields on record are as follows : — 



Year 


Grower 


Place 


Yield 
Bushels 


1857 . 

1889 . 
1889 . 
1910 . 


Dr. J. W. Parker 

Capt. Z. J. Drake 
Alfred Rose 
Jerry Moore 


Asylum Farm, Co- 
lumbia, S.C. 
Marlboro, S.C. 
Yates Co., N.Y. 
Winona, S.C. 


200.3 (a) 
255.1 (6) 
213.0 (c) 

228.7 (d) 



(a) This record has often been mentioned, but original data to verify 
it are not available. (6) and (c) These records and the method of grow- 
ing are given in The American Agriculturist, XLIX, March, 1890, p. 122. 
In each case the yield is field weight at husking and would have to be 
reduced at least 10 per cent for crib dry weight, {d) Field weight. 

1 Enfield, Edward. (1866.) Indian Corn, p. 54. 

2 The American Agriculturist, XVI : 238. 1857. 

3 Hartley, C. P. (1910.) U. S. Dept. Agr., Farmers' Bui. 414 : 14. 

57 



58 



COBN CROPS 




In all of the above cases, 
enormous quantities of com- 
mercial fertilizers and manures 
were used, but the instances 
illustrate the ability of corn 
to yield under the most fa- 
vorable soil conditions. 

The possible yield of corn if 
all conditions, both climatic 
and soil, were ideal for a sea- 
son, is probably in advance of 
any yield thus far recorded. 
The average yield of corn in 
the United States is 26 bushels 
per acre, only a small pro- 
portion of the possible pro- 
duction. 

CLIMATIC FACTORS AND 
GROWTH 

46. The principal elements 
of climate are sunshine, heat, 
rainfall, humidity, and wind. 

The climate favorable to 
corn is determined not so 
much by the amount as by the 
distribution of these factors, 
without fluctuations so great 
as to retard the gr-owth or to 

Fig. 22. — A single corn plant bear- 
ing 5 ears. Demonstrating the 
productivity of corn in favorable 
environment. 



CLIMATIC FACTORS 59 

reduce vitality.^ For example, one section might have 
sufficient average rainfall for a normal crop, but if this 
rainfall so fluctuated that at one season it was excessive and 
at another deficient, the normal crop might be reduced one- 
half or more; while another region with no more total 
rainfall but a better distribution would have a normal 
crop. In the same way, a single frost out of season or a 
hot wind might do great damage, although the average 
temperature "might appear favorable. Average annual 
rainfall, temperature, and sunshine are not a safe guide, 
unless the fluctuation of these factors during the growing 
season is also known. 

47. Length of the growing season. — Corn differs 
somewhat from other cereals in being able to adjust 
itself to the growing season. Wheat, oats, and barley 
grown in northern regions yield as well as when moved 
farther south, or even better. They have a somewhat 
longer growing season when taken south, but do not oc- 
cupy the available period as does corn. Some North 
Dakota varieties of corn will mature in 80 days, while 
Gulf States varieties often take 200 days. There are 
large corn regions with a growing season of more than 
200 days, but it does not appear that corn has been 
able in any region to utilize to advantage a longer 
growing period. 

As the tropics are approached, while frosts cease to 
limit the crop-growing season, at the same time there is 
usually a dry period which serves as a limit. In Mexico 
the growing season is limited in this way. 

All other factors being favorable, we may assume that 

^ The effect of fluctuation of rainfall on crop production is discussed in 
Bui. 130, Bur. Plant Indus., U. S. Dept. Agr., 41-49, in an article on 
" Cost of Crop Production under Humid and Dry Conditions." 



60 



CORN CROPS 



the ability of corn to yield will increase with the length of 
the growing season up to somewhere near 200 days. 
Therefore, for a good share of the present corn-belt of 
the United States, the length of the growing season is an 
important limiting factor. However, the varieties most 





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Fig. 23. — Length of growing season as indicated by the average date of 
last kilUng frost in spring and first killing frost of fall. (Bui. V., U. S. 
Weather Bureau.) 

coromonly grown in the South mature in 160 to 180 days, 
due to other limiting factors than frost, such as the rainfall 
not being sufficient for the entire season, poor drainage in 
early spring, or an unfertile soil. 

The accompanying chart, taken from Bulletin V of the 



CLIMATIC FACTORS 61 

United States Weather Bureau, shows the average length 
of the crop-growing season, or rather the time between the 
average date of the last killing frost in spring and the 
average date of the first killing frost in fall. 

The growing season of corn nearly coincides with the 
last probable frost of spring and the first probable frost of 
fall. For example, at Lincoln, Nebraska, where the aver- 
age time between killing frosts is given as 165 days, it is 
not considered advisable to grow a variety of corn taking 
more than 130 days to mature. The growing season for 
corn would be, in general, 20 to 30 days less than indicated 
on the chart ; or the 200-day limit would be central South 
Carolina. 

Also, there is great fluctuation in the length of growing 
season from year to year at any one point, and there is a 
general tendency to grow corn that will mature in the 
shortest season. Frear ^ made a study of meteorological \ 
conditions in relation to the development of corn at the 
•Pennsylvania station for three ears, 1887 to 1889. In 
his conclusions he makes this statement : " The difference 
in temperature between these two seasons (1887 and 1889) 
is almost equal to the difference in the mean July tempera- 
ture of Quebec and Boston ; of Burlington, Vermont, and 
Philadelphia; and of Fort Assiniboine, on the northern 
boundary of the United States, and Santa Fe, New Mexico. 
Then, too, in 1889 the rainfall was almost twice as great as 
in 1887, and the cloudiness at least 25 per cent greater." 

48. Relation of sunshine to growth. — The function 
of sunlight in furnishing the necessary energy for the 
various activities of plant growth was discussed in the 

1 Frear, W., and Caldwell, W. H. Relation of Meteorological 
Conditions to the Development of Corn. Perin. Agr. Exp. Sta., Ann. 
Rpt. 1889. 



62 CORN CROPS 

chapter on physiology. This has been well expressed 
b}^ Abbe, as follows : ^ — 

'^ The growth of a plant and the ripening of the fruit 
is accomplished by a series of molecular changes in which 
the atmosphere, the water, and the soil, but especially 
the sun, play important parts. In this process a vital 
principle is figuratively said to exist within the seed or 
plant and to guide the action of the soil, the water, and 
the air into such new chemical combinations as will 
build up the leaf, the woody fiber, the starch, the pollen, 
the flower, the fruit, and seed. . . . No plant life, not 
even the lowest vegetable organism, is perfected, except 
through the influence of the radiation from the sun. ... 
The radiation from any artificial light, especially the most 
powerful electric light, will accomplish results similar to 
sunlight ; therefore it is not necessary to think that life, 
or the vital principle, is peculiar to or emanates from the 
sun, but on the contrary that living cells utilize the radia- 
tions or molecular vibrations so far as possible to build 
up the plant." 

49. The intensity of sunlight. — The intensity of the 
sunlight received on the earth's surface is modified by the 
altitude of the sun, which determines the total hours of 
sunshine duration, by the atmosphere, and by the clouds. 

At high noon on a perfectly clear day, if there were no 
atmosphere, the earth's surface would receive the full 
effect of the sun's rays. When the sun is at zenith the 
atmosphere absorbs about 12.5 per cent of the sun's 
energy, so the efficiency may be expressed as .875, assum- 
ing the full effect to be 1. However, the sun is only at 
zenith for a moment, therefore, as it approaches the hori- 

1 Abbe, Cleveland. Relations between Climates and Crops. U. S. 
Weather Bureau, 1905 : 15. 



CLIMATIC FACTORS 



63 



zon, the altitude decreases, until at the horizon the light 
must penetrate 12 to 35 times as much atmosphere, and 
its total effect is weakened to about one-filth the full 
effect at 90 degrees. The effect at different altitudes is 
expressed in the following selected altitudes : ^ — 

TABLE XI 



Altitude of Sun 
Degrees 


Thickness of 

Atmosphere 

Laplace Formula 


Intensity of Direct 

Sunshine; Calories per 

Minute, per Sq. Cm. 

ON Surface Normal to Rays 




4 „ , . - . . 
10 ..... . 

30 „ .... . 

50 ..... . 

90 


35.50 
12.20 
5.70 
1.995 
1.305 
1.000 


0.359 
1.293 
1.868 
2.275 
2.364 
2.403 



From the equator to 40 degrees latitude, the total sun- 
shine received at a given place from March to September 
is about one-third of the total possible sunshine at that 
point if the sun stood at zenith during the hours of day- 
light. In the northern latitudes the longer days of mid- 
summer compensate for the lower altitudes of the sun, so 
that during the months of June and July, as much heat 
is received at the north pole as at any lower altitude. 
In fact, for a period of about 90 days, more heat units 
are received at the north pole than the equator, but due 
to the great amount of ice is not sufficient to raise the^ 
temperature above freezing. The relative quantities of 
heat received at different latitudes in the Northern Hemi- 
sphere are shown by the following table, as calculated by 
Aymonnet : ^ — 

1 Abbk, loc. cit., p. 85. 2 iijid,, p. 92. 



64 



COEN CROPS 
TABLE XII 











Latitude 
























0° 


10° 


30° 


50° 


70° 


80° 


90° 


March 20-31 . . 


3.7 


3.7 


3.3 


2.3 


1.1 


0.6 


0.2 


April 


10.0 


10.6 


10.1 


8.0 


5.4 


3.9 


3.4 


May 


9.8 


10.7 


11.7 


10.5 


9.0 


8.6 


8.7 


June 


9.2 


10.4 


11.9 


11.3 


10.7 


11.0 


11.1 


July 


9.7 


10.7 


12.1 


11.3 


10.3 


10.1 


10.2 


August .... 


10.1 


10.7 


10.9 


9.2 


6.8 


5.9 


5.8 


September 1-23 . 


7.7 


7.8 


7.1 


5.2 


2.7 


1.5 


0.9 


Total .... 


60.2 


04.0 


67.1 


57. S 


46.0 


41.6 


40.3 


Total possible if 
















sun stood at 
















zenith 


186.0 


186.0 


186.0 


186.0 


186.0 


186.0 


186.0 



It is apparent from the above data that up to 70 degrees 

north latitude there is sufficient sunshine during the 

summer months to produce corn, were it not for other 

hmiting factors, as low temperature due to a cold soil and 

cold air currents. 

:\ The data presented thus far are on the basis of per- 

1 fectly clear days, but the presence of clouds reduces the 

y sunshine. At Montsoris, France, careful records for the 

corn-growing season kept from 1875 to 1885 showed 

only about 40 per cent of the possible intensity of sunshine, 

due to cloudiness. Corn under such conditions does not 

grow well, but requires, even at that latitude, what might 

be termed a rather " sunny " climate. 

We may conclude that except where cloudiness prevails 
for half the time, there is sufficient sunshine for corn pro- 
duction even up to 70 degrees latitude. 

50. Relation of rainfall to growth. — The transpiration 
of 14 to 20 tons of water is required to produce one bushel 



CLIMATIC FACTORS 



65 



of corn. For a jdeld of 50 bushels per acre, this equals 
7 to 10 acre-inches of water. ^ With a larger crop the water 
used would be increased proportionally. Under field condi- 
tions there must be added to this whatever loss may take 
place through run-off, evaporation from the soil, and 
seepage. King found that a yield of 7000 to 8000 pounds 





MoLI 


Jure 


Ju/u Jus. 


Se/l 


•x» 








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ed 









Fig. 24. — Chart showing relation between storage water in the soil and 
consumption of water by the corn plant each month. The storage 
capacity of the soil is exhausted before the end of July. The crop is 
therefore dependent on July and August rainfall. 



of dry matter per acre (approximately a 50-bushel yield) 
required about 12 acre-inches under field conditions. In 
this case the loss by seepage, run-off, and evaporation 
must have been about 5 acre-inches (assuming 7 inches 
used by the crop), but this will vary with the soil, culti- 
vation, distribution of rainfall during the growing season,/ 
and amount of storage water in the soil at planting time J 

1 Montgomery, E. G. Ann. Rpt. Nebr. Agr. Exp. Sta. 1910 : 155. 
King, F. H. Ann. Rpt. Wis. Agr. Exp. Sta. 1902 : 99. 
F 



66 CORN CROPS 

An average corn soil in good tilth will store about 5 to 
6 inches of available water in the upper 4 feet. A 50- 
bushel crop would then require at least 6 inches addi- 
; tional rainfall during the growing season, and prob- 
I ably more than this, as corn seldom grows well when 
, required to exhaust the soil moisture to low limits. A 
75-bushel crop would require an additional rainfall of 
10 inches and a 100-bushel crop at least 15 inches during 
the growing season, in addition to that stored in the soil. 
When the run-off is large, as on hills or with torrential 
rains, or when there is seepage, the above estimate should 
be increased. This estimate is on the assumption that 
the soil is fertile. No amount of rain would make a poor 
soil productive. For example, the average rainfall for 
June, July, and August in the eight surplus corn States 
is about 12 inches, but the average yield is 28.5 bushels. 
Other factors than total rainfall here limit the yield, 
one important factor being that the rainfall is not always 
properly distributed. 

51. Any system of culture that will serve to prevent 
run-off on the one hand and to decrease evaporation on 
the other, will proportionally increase the available water 
supply for the crop. 

Not only the total amount, but the distribution, of the 
I season's rainfall is of great importance. Figure 25 shows 
the precipitation for June, July, and August for a period 
of fifteen years and the yield for eight surplus corn States, 
namely, Ohio, Indiana, Illinois, Iowa, Nebraska, Kansas, 
Missouri, and Kentucky.^ 

Here is shown a very close relationship between rainfall 
and yield, when large areas are considered. 

1 Smith, J. Warren. Relation of Precipitation to Yield of Corn. 
U. S. Dept. Agr. Year Book, 1903 : 215-224. 



CLIMATIC FACTORS 



67 



Professor Hunt/ at the Illinois Agricultural Experiment 
Station, grew 18 plats of corn which yielded 32 bushels 
per acre. The next year, and on the same plats and with 
the same varieties of corn, the yield was 94 bushels per 
acre. The rainfall from May to September was 13 inches 
the first season and 22.5 inches the second season. 























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^\ 


/; 












\ 
















\\ 


1 












\ 






























1 






00 c 
CO 

00 


§ 1 

H 1- 


-t r 


H C 

7i C 


H r 


^1 

7i C 
01 


T 

1 c 

o 

H r- 


-5 C 




H r 


o 



H r 





:5 E 

c 

-( r- 


I I 


5 I 

H r 


I 



Fig. 25. 



Rainfall of June, July, and August, and yield of corn per acre. 
(Year Book, U.S. Dept. Agr., 1903.) 

Average yields of corn 1S8S to 1902. 

Average rainfall for June, July, and Augu.st. 



The seasonal rainfall and its distribution is the most 
important climatic factor in corn production. With suffi- 
cient rainfall, properly distributed, it is probable that the 
present yield of corn would be increased 50 to 100 per cent. 
We cannot control the rainfall or its distribution during 
the season, therefore farm practice must make the best 
use of rainfall as it comes. The present rainfall is suffi- 
cient for two to three times the present yield, if it is con- 
served and the soil is in the most fertile condition. 

1 Hunt, T. F. Cereals in America, p. 207. 



CHAPTER VI 
RELATION OF SOILS TO GROWTH 

Most of the good corn soils of the United States are 
deep black loams, well drained, well supplied with organic 
matter, and rich in available nitrogen, phosphates, and 
potassium. 

52. The soil may be regarded as a medium for holding 
minerals and water in an available form for the plants as 
needed. Natural productive soils are those that in a 
state of nature contain all the mineral elements and organic 
matter necessary, and are supplied with sufficient natural 
rainfall. 

In some virgin soils, as the deep black loam soils of the 
Mississippi, Ohio, and Missouri river drainage basins, 
there is sufficient of all mineral elements in an available 
form for the maximum production of corn. Even in 
these soils, however, maximum production is seldom at- 
tained, as the rainfall is not always properly distributed, 
nor even sufficient. 

Corn especially enjoys a large supply of nitrogen and 
will flourish in soils so rich in available nitrogen that other 
cereal crops would produce an excessive amount of straw, 
probably lodging and making a poor yield of grain. Corn 
is able to make use of fertility furnished through the de- 
caying of coarse organic matter, as manure or sod land ; 
while other cereals, as wheat and oats, require for best 
results a more advanced state of decomposition, with 
the elements more easily available. 



RELATION OF SOILS TO GROWTH 



69 



The ability of corn to utilize to advantage large quan- 
tities of fertilizer and manure is illustrated in the cases 
cited on page 57 of the four maximum yields of corn 
produced. 




Fig. 26. — Corn as it grows on the best type of natural corn land. 



70 CORN CROPS 

CAUSES OF LOW PRODUCTION 

53. Assuming rainfall to be sufficient, a good corn soil 
should produce 75 bushels per acre. Only a small per- 
centage of the corn land in the United States will yield 
this at present, due to certain causes which may be 
summarized as follows : — 

1. Poor drainage. Corn suffers more than do other 
cereals from poor drainage, as it requires a " warm " 
soil, and also available nitrogen in rather large quantities. 
Nitrifying processes are hindered in waterlogged soils. 

2., Surface soil depleted through erosion, very com- 
mon on roUing lands in regions of large rainfall. 

3. Soil once fertile but depleted through constant crop- 
ping without return of organic matter or minerals. 

4. Soils which in a virgin state were deficient in organic 
matter or lacking in some mineral element. 

Each of the above soils will be found deficient in one 
or more of the following : — 
(a) Drainage. 
(6) Organic matter. 

(c) Nitrogen. 

(d) One or more mineral elements. 

(a) is corrected by drainage, (6) and (c) by manure or 
the growing of legumes, (d) by manure or commercial 
fertilizers. 

CLASSIFICATION OF CORN SOILS IN THE UNITED STATES 
ACCORDING TO PRODUCTIVENESS 

54. For the regions east of the Rocky Mountains the 
corn soils may be classed according to productivity into 
four general groups. 

1. Soils capable of producing 75 bushels or more per 



RELATION OF SOILS TO GROWTH 71 

acre, with normal rainfall of region such as the black 
loam bottom land soils of the Mississippi drainage basin, 
and certain areas of black upland or drained swamps. 
This soil is well drained, well supplied with organic mat- 
ter, minerals, and rainfall, and usually commercial fertil- 
izers will show little or no effect. The total area is small, 
probably not greater than 1 per cent of the Corn Belt. 
This may be termed the ideal corn soil. 

2. Soils producing 35 to 50 bushels per acre, with favor- 
able climatic conditions. 

(a) This includes the greater part of the cultivated 
lands in the surplus corn States of Ohio, Indiana, Illi- 
nois, Iowa, Nebraska, Kansas, and Missouri. These 
soils have been cropped for fifty to seventy-five years, 
during which time the ability to yield has decreased 
25 to 50 per cent. All these soils respond quickly to an 
application of manure, or are increased 25 to 50 per cent 
in productivity by growing a crop of clover or alfalfa. 
They seem to need organic matter and available nitrogen 
more than anything else. The supply of minerals is gen- 
erally sufficient, but in many cases the application of both 
potassium and phosphates gives increased yields, though, 
as a general rule, the increase is not sufficient to be profit- 
able. Rotation, the use of legumes, and manure are to 
be relied on at present as the principal means of main- 
taining or increasing the yield. 

(6) All the '' good corn land " through the Eastern and 
Southern States is also included in this class. 

3. Land producing 25 to 35 bushels under favorable 
climatic conditions. 

(a) Through the Eastern and Southern States are 
large areas which are fairly productive when first brought 
under cultivation, but which have been cropped for 



72 CORN CROPS 

seventy-five years or more. Erosion also has played an 
important part in depleting the rolling lands. The 
supply of organic matter is generally low, and in many 
cases the lands need underdrainage. Throughout the 
" Corn Belt " there are also considerable areas in this 
class. 

(6) Soils naturally not very productive, through lack 
of one or more mineral elements or of drainage. 

In general, legumes and manure must be the principal 
means of increasing and maintaining the productivity 
of this land; but when a mineral element is lacking, as 
lime, potassium, or phosphorus, it will usually be neces- 
sary to add this in the form of commercial fertilizer. 

4. Land producing less than 20 bushels per acre. 

(a) Through the Eastern and Southern States are large 
areas which, through continuous cropping and erosion, 
are low in yield. In addition to the prevention of ero- 
sion, the same general treatment as is recommended for 
the previous class may be used. 

(6) Land in regions of deficient rainfall. Where there 
is less than eight inches during the growing season, lack 
of moisture becomes a hmiting factor in corn production. 
From Dakota to Texas there is a large area with a fertile 
soil but an annual rainfall of only 18 to 25 inches. In 
these soils conservation of moisture is the most important 
phase of soil treatment. 

SUMMARY 

55. The ability of corn to yield is indicated by certain 
maximum yields, when 150 to 200 bushels per acre have 
been harvested. Regarding climatic factors, there is 
usually enough sunshine and, in most of the Corn Belt, 
a sufficient total rainfall ; but the latter is not often dis- 



RELATION OF SOILS TO GROWTH 73 

tributed in the best way for the growth of corn. A large 
share is lost by run-off, and the supply is seldom properly 
conserved by preparation of the land and by cultivation. 

The length of growing season is a limiting factor, where 
the season is less than 180 days. 

The principal cause of low production is lack of avail- 
able fertility in the soil. 

Climatic factors are mostly out of our control except 
that the effect of rainfall may be modified, hence our 
principal efforts in increasing corn production should be 
in the treatment of soil. 



SECTION III 

IMPROVEMENT AND ADAPTATION OF THE 
CORN PLANT, AND ENVIRONMENT 



CHAPTER VII 
EARLY CULTURE OF CORN 

Indian corn was unknown to Europeans until the 
discovery of America. At that time it was found to be 
in general cultivation by the Indians of both North and 
South America. In fact, corn was the principal crop 
cultivated by the native Americans, as they had neither 
oats, wheat, nor barley, and very few of the cultivated 
vegetables. The most ancient evidence of the culture 
of corn is found on the western coast of South America 
and in Mexico. In Peru specimens of corn have been 
found in connection with ancient ruins or geological forma- 
tions, which are probably at least two or three thousand 
years old. The fact that corn was buried in the tombs, as 
well as other evidence, indicates that it had an important 
place in the religious ceremonies of this semicivilized 
people and was probably their most important cultivated 
plant. 

56. During the fifteenth century the earliest white ex- 
plorers of America took corn back to Europe, where in 
time it came to be extensively cultivated, especially in 
those countries surrounding the Mediterranean Sea. 

When corn culture began to spread in Europe it had 
many curious names, as Italian corn, Turkish corn, 
Spanish wheat, Guinea wheat, and others, probably indi- 
cating the places where its culture first became extensive. 

Collins has recently described a type of corn cultivated 

77 



78 COBN CROPS 

in China. References to corn in Chinese literature indi- 
cate its culture in China for some 350 years, although 
just how or when corn was introduced into China is a 
question. 

When the first white settlers came to America, at 
Jamestown (1607) and Plymouth (1620), they at once took 
up the culture of corn, procuring the seed and learning the 
method of culture from Indians. It soon became the 
most important cereal crop of the colonists, gaining its 
popularity by reason of its simple culture, its sure produc- 
tion, and the ease with which the crop was harvested and 
preserved. 

DEVELOPMENT OF VARIETIES 

57. In 1898 Sturtevant listed 507 named varieties and 
163 synonyms. It was not possible for Sturtevant to 
secure all varieties in his day, and it is probable that a 
complete catalogue of all varieties at present would 
almost double this number. Of these varieties listed by 
Sturtevant, 323 were classified as dent corn, 69 as flint 
corn, 63 as sweet corn, 27 as soft corn, and 25 as pop corn. 

It is known that at least a few varieties of all the five 
principal groups were in cultivation when America was 
discovered, with the possible exception of sweet corn. 
The earhest record we have of sweet corn is in 1779, when 
it was mentioned as being in cultivation near Plymouth, 
Mass.^ However, it could easily have been overlooked 
by the early explorers and has probably been in existence 
for a long period. 

It appears that the Indians inhabiting what is now the 
northern part of the United States and southern Canada 

1 Sturtevant, E. L. U. S. Dept. Agr., Office of Exp. Sta., Bui. 
67 : 18. 



EARLY CULTURE OF CORN 79 

cultivated mostly an eight-rowed flint corn, and in a 
limited way an early variety of soft corn commonly known 
to-day as " squaw " corn. The Indians of the south- 
western United States, Mexico, and South America cul- 
tivated the different varieties of soft corn principally, 
and also, in a limited way, flint corn, pop corn, and dent 
corn. The dent corn, however, does not appear to be like 
our modern dent of the deep-grained, large-eared varieties, 
such as Boone County White, but of a rather shallow- 
grained type with a square grain or a grain even broader 
than long. There was also a very rough, deep-grained 
type with a short ear, similar to our Shoe Peg corn of the 
present day. 

By the year 1800 there were a number of recognized 
varieties of flint corn, mostly of eight-rowed types, and 
a few dent and soft corns cultivated by the colonists. 
At least one variety of sweet corn (the Papoon eight- 
rowed) and a few pop corns were known, but were not 
in general cultivation. '^ 

Bonafous, in 1836, and Metzger, in 1841, both published 
classifications and descriptions of corn indicating that at 
least all the characters of corn known at present were to 
be found among the varieties at that time. Metzger 
made twelve races, and mentioned varieties ranging in 
height from 18 inches to 18 feet. Since 1840 there has 
been a rapid expansion of corn culture and great interest 
has been shown in the development of varieties adapted 
to various conditions and uses. It may be safely estimated 
that perhaps three-fourths of the present varieties of corn 
have been developed since 1840. The history of sweet 
corn is an excellent example. Following are listed the 
authorities and the number of varieties of sweet corn that 
each knew, and the year of his observation : — 



80 CORN CROPS 



Date 



1779 

1832 
1836 
1853 

1858 
1866 

1884 
1898 



AUTHORITT 



Bridgman .... 

Bonafous 

U. S. Patent Office Rpt. 
Klippert ..... 

Burr ...... 

Sturtevant .... 

Sturtevant . . . 



Number of 
Varieties 



1 

1 
1 

3 

6 

12 

33 

63 



There has been a similar rapid development of dent 
varieties. 

In 1866 Edward Enfield ^ made a list and description of 
corn varieties, which he said represented '^ most of the 
varieties in use, and all that are likely to be of practical 
value to the farmer." Of field corns he describes 20 
varieties, 13 of which were flints, 3 broad-grained dents of 
12 or 14 rows, 1 flour corn, and 3 gourd seed varieties 
grown in the South. However, J. S. Leaming had begun 
selecting '' Leaming " corn in 1826 and Mr. Reid began 
selecting his corn in the late forties. With the rapid de- 
velopment of corn culture, after the Civil War, the modern 
dent type came to be generally used throughout the Corn 
Belt States ; although the flint corns are still the principal 
corns in the Northern States, where the season is too 
short for the large dents. 

58. Early methods of modifying varieties. — Probably 
the means that has been most commonly used in the past 
was either to hybridize two varieties and select some type 
from this hybrid for several years until the type was fixed, 

1 Enfield, Edward. (1866.) Indian Corn. D. Appleton & Co., New 
York. 



EARLY CULTURE OF CORN 81 

or to start a systematic selection in some recognized variety. 
One of the earliest reports of the origin of a variety is 
given by Mr. C. H. Heydrick, of Utica, Penn., in the Agri- 
cultural Report of the Commissioner of Patents for 1853. 
As most early varieties were originated by some such 
method, the quotation is here given : — 

"With regard to the changes which may be wrought in a 
variety by cultivation, I cannot give a better illustration than 
the history of the 'Vermont Yellow,' that I cultivated a few years 
ago. Its characteristics were, a short stalk, slender above the 
ear, strong below, ears small, with eight rows, thick at the butt 
end, growing near the ground, and frequently having a stem two 
feet in length. My plan of selecting seed from this variety was 
to choose from such stalks as produced two or more ears, reject- 
ing those with large butt ends, and such as were not set close to 
the stalk. Such seed was hard to find the first year. The second 
year nearly one-half of the stalks produced two ears, and there 
were fewer long stems and large butt ends. A milder climate 
had also produced another change. Many ears appeared with 
ten or twelve rows. This induced me to improve the size of 
the corn and accordingly I selected as before, adding such ears 
as contained more than eight rows, together with a few ears 
of a larger sort. Continuing this system for a few years I ob- 
tained a variety characterized by the following marks : stalks 
light, seldom exceeding six feet in height ; strong below the ears, 
slender above ; ears containing from ten to fourteen rows, and 
from two to three ears to a stalk, more frequently than a less num- 
ber. From these facts it will be seen that a mixed variety may 
be produced, possessing all the desirable qualities of several 
old ones. But such a new variety will require attention a few 
years, to prevent it from degenerating into one of the original 
sorts, after which, I think, the variety will become as permanent 
as any other." 

Many of the early corn breeders used the above method 
of selecting out some type from an old variety. It is 
probable, however, that many of the variations found 



82 



CORN CROPS 



were due to natural hybridization, as this is likely to take 
place to some extent in a neighborhood where any two fields 
are less than twenty to forty rods distant from each other. 




Fig. 27. — Relation of type to climate. The short type on left is better 
adapted to dry regions than the tall, more slender type. The tall 
type is adapted to warm, more humid regions. 

Crossing as a means of securing new forms was often 
practiced, and a method is outlined by Enfield (1866) .^ 

1 Enfield, Edward. (1866.) Indian Corn, pp. 70-74. 



EARLY CULTURE OF CORN 83 

59. Natural selection and acclimatization in producing 
varieties. — It is well known that each region of the United 
States has corn of a type more or less peculiar to that 
section. For example, in the Gulf States, corn grows 
very tall, frequently 15 to 18 feet, with ears 6 or 8 feet 
from the ground; in the Corn Belt States the plant is 
about two-thirds as high ; while along the Canadian border 
the height is 5 to 8 feet, and ears are often less than 2 feet 
from the ground. Also the growing season will vary from 
200 days in the South to 80 days in the North. If a 
variety of corn be moved from one section to another, it 
will become from year to year more like the native corn 
of the region. 

It is not known how much of this change may be due 
to actual modification of the plant by environment, but 
it is probable that it is brought about chiefly through 
wide variations and through both natural and artificial 
selection. When a variety is moved from one climate or 
soil to another, it does not yield so well the first year as 
later, when it becomes " acclimatized." When planted 
first in the new location, there are certain plants much 
better suited than others to the new conditions. These 
would produce the best ears and be selected for seed, thus 
preserving the best-adapted type. An excellent example 
is cited from Nebraska,^ where a variety of corn from 
Iowa was grown in central Nebraska for two years and 
as a result decreased about 12 inches in height, while the 
ear was almost 8 inches lower; the yield of grain, how- 
ever, increased. 

If the same variety be widely distributed and grown 
for a few years, and seed again collected for compari- 
son under the same conditions, it will be found that 

1 Nebr. Agr. Expr. Sta., Bui. 91 : 29. , 



84 CORN CROPS 

each region has had some effect in modifying the 
original type, 

SUMMARY 

60. The early culture of corn probably originated in 
the high plateau region of southern Mexico, about the 
beginning of the Christian Era. From here it spread 
north and south, its culture being general throughout 
North and South America by the year 1000 a.d. 

The Indians grew flint and flour corns chiefly, probably 
because of their keeping and germinating qualities. 

Most of the modern varieties in general use in North 
America have been developed during the past century, 
though the principal types have probably been in existence 
for many hundred years. 

Selection, both artificial and natural, accounts for the 
origin of many varieties ; while crossing, sometimes in- 
tentional, but often accidental, has furnished a great many 
variations from which to choose. 

References on early culture : — 
See, References on early history ; p. 24. 

References on origin of varieties : — 
Mo. Agr. Exp. Sta., Bui. 87 : 113. 
Nebr. Agr. Exp. Sta., Bui. 83 : 12. 
U. S. Dept. Agr. Yearbook, 1907 : 230. 
Bowman and Crossly. Corn, p. 424. 



CHAPTER VIII 
IMPROVEMENT OF VARIETIES 

Perhaps no other cultivated plant in America has been 
the object of so much study and attention, with the object 
of adapting it to the various soils, climates, and needs of 
man, as the corn plant. 

The plant is large, interesting, lends itself well to de- 
tailed study, and responds readily to care or selection. 
From earliest domestication by white men, there has 
always been a large number of growers, giving time and 
attention to its improvement. An infinite variety of 
forms has been developed. Every detail of the plant has 
been studied as to its possible economic value, in improv- 
ing the yield or quality of grain or forage. Almost every 
possible theory has been held by practical growers regard- 
ing the relative value of different types of ear, leaf, stem, 
or other parts of the plant. Of recent years, good scien- 
tific study has also been made at many of the experiment 
stations. In the following pages it is attempted to sum 
up what is known to be of practical value in type of plant 
or selection of methods. 

. 61. Type of ear. — From the earliest times it is probable 
that some attention has been given to the types of ear 
selected for seed. The originators of varieties have usually 
had a well-defined type in mind, for which they have 
selected. There is no evidence that the type of ear chosen 
has had a direct relation to yield, since equally good 

85 



86 CORN CBOPS 

results have been secured with very diverse types, as the 
tapering Learning, the cylindrical Reid's Yellow Dent, 
the shallow Hickory King, and the extremely deep- 
grained Hackberry. Flint corns and the small-eared, 
prolific corns have also given excellent results. 

Since several investigators have studied ear characters 
in relation to yield, all data verify the experience of 
Hartley, which he summarizes as follows : ''A careful 
tabulation of yields as compared with other ear characters, 
covering six years' work with four varieties, embracing 
in all more than 1000 ear-to-row tests of production, in- 
dicates that no visible characters of apparently good seed 
ears are indicative of high yielding power." Since white 
men began corn culture, no doubt some gain has been 
made in ability to yield, but the fact that large ears have 
been selected will account for this. As the ear represents 
the producing ability of a plant, all other things being 
equal, the selection of large ears would preserve the most 
productive strains. 

Varieties having a medium depth of grain mature 
better and keep better in the crib than very deep-grained 
types, and, since they seem to yield as well, they are to be 
preferred. 

62. Type of plant. — While some study has been given 
to the character of plant, no definite relationship has been 
proved, which would justify the consideration of the plant 
in seed selection, other than this : the average type in an 
acclimated variety will yield better than either extreme. 
The average type, however, varies in different regions. 
For example, on the west edge of the Corn Belt, with a 
rainfall of 22 to 25 inches (central Nebraska, Kansas, and 
vicinity), the plant when acclimated is short, stocky, 
with the ear rather low. To select here for tall plants 



IMPROVEMENT OF VARIETIES 87 

with the ear borne high would not be in harmony with 
natural conditions, and experience has shown that varieties 
having these characters do not yield so well as the native 
type. Also, at the Nebraska station, when comparison 
was made between broad-leaved and narrow-leaved 
strains in dry years, there being an excess of sunshine and 
limited water supply, the largest yields were obtained from 
narrow-leaved strains.^ In one year, with excessive rain- 
fall, broad-leaved types gave larger yields. While broad 
leaves elaborate starch, they also evaporate water at a 
rapid rate ; hence, the most desirable leaf area on corn 
plants must be a balance between the moisture supply 
on the one hand and sunshine on the other. 

While under rather abnormal conditions for growth, 
as a dry climate, attention must be given to the character 
of plant growth, yet under normal conditions a wide range 
is permitted. In Illinois, where selection for height of ear 
was continued for six years, there was no marked difference 
in yield between the high-ear and low-ear types, and the 
same was also true when angle of ear was considered. 

It may be assumed that when selection is made for 
yield, all other characters of the plant will adjust them- 
selves under the given conditions ; so that ultimately the 
type of plant giving best yield under those conditions will 
result. However, under certain conditions in the South 
the ears are borne very high, and in the North, in some 
cases, the ears are borne very low. In both these cases, 
for convenience in harvesting, it would be well to select 
for a more desirable height of ear. There are many in- 
stances where selection to modify some character of the 
plant would be justified, even though the yield was not 
affected. 

1 Nebr. Agr. Exp. Sta., 24th Ann. Rpt., p. 158. 



88 CORN CROPS 

SYSTEMS OF SELECTION 

63. Mass Selection in corn is the method of selecting 
from a large field a number of individuals that conform 
nearest to some ideal type. Seed of these plants is mixed 
together and planted a second year and again a large 
number of ears are selected and mixed for planting an- 
other year, and so on for many years. 

It was discovered, however, that of two ears much alike 
in appearance, perhaps one might >deld 25 per cent to 50 
per cent more than the other when used as seed corn. 
The importance of testing each ear separately was at once 
recognized. 

In pedigree selection after the first mother ears are 
selected, a separate record is kept on the performance of 
each ear or its progeny. For example, if it is desired to 
select for a type bearing ears low on the stalk, a hundred 
such ears might be selected from a large field. If mass 
selection is practiced, they are mixed together and planted 
the following year and the method continued for several 
years. If pedigree selection is followed, each ear is planted 
in a separate row and a record made of the percentage of 
low ears produced by each mother ear. Seed ears are 
only saved from those mother ears producing a large 
percentage of low ears, the remainder being discarded. 
Perhaps ten mother ears out of the first 100 will be found 
to transmit the desired quality. From the progeny of 
these ten ears, 100 ears may again be saved, each to be 
planted in a separate row. This may be continued for 
several years, the performance record being kept for every 
year. By keeping a record on each family separate it 
will be possible to gradually discard those families not 
transmitting the desired quality and keep only those that 
are most desirable. 



IMPROVEMENT OF VARIETIES 89 

64. Results with mass and pedigree selection. — With 
all obvious characters, such as height or angle of ear, the 
same results to a certain degree will be obtained by either 
method ; but these results should be secured in less time 
by the pedigree method. 

This is rendered more comprehensive by conceiving a 
cornfield to be a mixture of types, and selection as a 




Fig. 28. — Selection for high and low ears at the 111. Exp. Sta. The tape 
shows height of ear. The original selection was from the same field 
and had been continued for five years when this pictm-e was taken. 

method of isolating these types.^ It is clear that pedigree 
breeding is a more rapid method of isolation than contin- 
uous selection. 

With selection for yield it is possible that no result would 
be secured with mass selection, unless there were some 
obvious character of the plant closely associated with 
yield; while on the other hand, rapid progress might be 
expected from pedigree cultures, as a record would be 
kept on the performance of each individual. 

1 The theory of isolating pure types by mass and pedigree selection 
is expounded at length by De Vries, in Plant Breeding. Open Court, 
Chicago. 



90 



CORN CHOPS 



65. Mass Selection. — The result of mass selection in 
corn is well illustrated by the history of any of the older 
varieties, as Learning, Reid, or Boone County White. 
After many years' selection, the breeder succeeded in 
producing a more or less uniform type. 

For example, the Learning variety was originated by 
Mr. J. S. Leaming, of Hamilton, Ohio :^ '^ After fifty-six 
years' selection, Mr. Leaming produced a corn having as 
variety characteristics a distinctly tapering ear, fairly 
large butts, rather pointed but well-covered tips, with 
kernels of a deep yellow color, with very irregular rows." 

Hartley produced a corn with twisted rows by select- 
ing such ears from the field. At the Nebraska Agricultural 
Experiment Station, a shallow-kerneled tjrpe of corn was 
fixed by continuous selection after five years. ^ 

66. Pedigree selection. — A striking example has been 
reported from the Illinois station.^ Two sets of Leaming 

TABLE Xm 

General Averages of Crops produced in Corn Breed- 
ing, FOR High Ears and for Low Ears 





Height 


OF Ear 


Height < 


>F Plant 


Year 












High-ear Plat 


Low-ear Plat 


High-ear Plat 


Low-ear Plat 




Inches 


Inches 


Inches 


Inches 


1903 . . . 


56.4 


42.8 


113.9 


102.5 


1904 . . . 


50.3 


38.3 


106.2 


97.4 


1905 . . . 


63.3 


41.6 


128.4 


106.5 


1906 . . . 


56.6 


25.5 


116.3 


86.0 


1907 . . . 


72.4 


33.2 


130.4 


99.7 


1908 . . . 


57.3 


23.1 


114.0 


79.3 



1 Mo. Agr. Exp. Sta., Bui. 87 : 113. 

2 Nebr. Agr. Exp. Sta., BuL 113 : 20. 

3 111. Agr. Exp. Sta., Bui. .132. 1909. 



IMPROVEMENT OF VARIETIES 



91 



ears, one borne high on the stalk and the other low, were 
selected in tlie fall of 1902. Continuous selection was 
practiced for six years, when a difference of about three 
feet in height was secured in the average crop, as shown by 
the table on previous page. 

Results were also obtained when selection was made 
to increase or decrease the angle of the ear, the erect-ear 
strain and declining-ear strain having average angles of 
46° and 88.50° respectively, after six years. 

67. Selection for composition. — Composition can also 
be modified by continuous selection, as shown by the 
Illinois station.^ Ears of a single variety were selected for 
high-protein, low-protein, high-oil, and low-oil content, 
respectively. After ten years' selection, the high-protein 



TABLE XIV 

Ten Generations of Breeding Corn for Increase and 
Decrease of Protein and Oil 



Year 


High- 
protein 

Crop 
Per Cent 


Low- 
protein 

Crop 
Per Cent 


Dif- 
fer- 
ence 


High- 
oil 
Crop 
Per Cent 


Low- 
oil 
Crop 
Per Cent 


Dif- 
fer- 
ence 


1896 .... 


10.92 


10.92 




4.70 


4.70 




1897 








11.10 


10.55 


0.55 


4.73 


4.06 


0.67 


1898 








11.05 


10.55 


0.50 


5.15 


3.99 


1.16 


1899 








11.46 


9.86 


1.60 


5.64 


3.82 


1.82 


1900 








12.32 


9.34 


2.98 


6.12 


3.57 


2.55 


1901 








14.12 


10.04 


4.08 


6.09 


3.43 


2.66 


1902 








12.34 


8.22 


4.12 


6.41 


3.02 


3.39 


1903 








13.04 


8.62 


4.42 


6.50 


2.97 


3.53 


1904 








15.03 


9.27 


5.76 


6.97 


2.89 


4.08 


1905 








14.72 


8.57 


6.15 


7.29 


2.58 


4.71 


1906 








14.26 


8.64 


5.62 


7.37 


2.66 


4.71 



1 in. Agr. Exp. Sta., BuL 128. 1908. 
U. S. Dept. Agr., Farmers' Bui. 366 : 314. 



92 



CORN CROPS 



selection contained almost twice as much protein (14.26 
to 8.64) as the low, while the high-oil selection contained 
almost three times as much oil as the low (7.37 to 2.66). 
At the Nebraska station, pedigree selection for yield was 
practiced for five years in one case and two years in 
another, and an increased yield, amounting to nine 
bushels was secured in both cases. 



TABLE XV 

(Class I) Result of Five Years' Pedigree Selection for 
Yield. Bushels per Acre 





1907 

Bushels 


1908 

Bushels 


Average 
Bushels 


Selected strains 

Check plats (original stock) . . 


82.0 
72.5 


66.0 
59.0 


74.0 
65.7 


Difference 


9.5 


7.0 


8.3 


(Class II) Result of Two Yea 

Yield 


RS' Pedig] 


REE Selection for 




1908 

Bushels 


ftpipfifprj strains 


68.0 


Check plats (original stock) 


59.0 


Difference 


9.0 







References on type of ear and stalk : — 
Ohio Agr. Exp. Sta., Bui. 212. (1909.) 
Nebr. Agr. Exp. Sta., Bui. No. 91, p. 12 (1906) ; No. 112, p. 17 

(1909). 
Nebr. Agr. Exp. Sta., Ann. Rpt. 1910, p. 154. 
CorneU Bui. 287. (1910.) 
111. Bui. 132. (1909.) 
Hartley, C. P. Yearbook U. S. Dept. Agr. 1909, pp. 309-320. 



IMPROVEMENT OF VARIETIES 93 

References on methods of continuous pedigree selection : — 
111. Exp. Sta., Buls. 82, 100, 128. 
Conn. Exp. Sta., Buls. 152 and 168. 
Ohio Exp. Sta., Circ. 66. 
Nebr. Exp. Sta., Bui. 112. 

Directions to Cooperative Corn Breeders. Hartley, C. P, 
(1910.) Bur. of Plant Industry, Wash., D.C. 



CHAPTER IX 

METHODS OF LAYING OUT A BREEDING- 
PLAT 

While the principle underlying systematic selection is 
simple, it has been more difficult to develop good methods 
for carrying out the selection work in order to avoid error. 
Breeding-plot methods have had a steady development, 
each step in advance being intended to overcome some 
source of error or to develop some new possibilities. 

In the reference on ^' Methods of pedigree selection," 
given on a previous page, several methods for conduct- 
ing a breeding-plat are given. The development of the 
breeding-plat plan may be summarized in the following 
brief way, beginning about 1895 : — 

68. 1. Select a number of mother ears and plant in 
parallel rows, taking the yield of each row and saving 
seed ears from this row to continue in the same manner. 
(See 111. Agr. Exp. Sta., Bui. 55.) 

2. The above plan was found to favor inbreeding and 
close breeding, with danger of decreasing yield. In order 
to avoid .this it was recommended to detassel every odd 
row, sowing seed from only the detasseled rows. Thus, 
every odd row became a dam while the even rows would 
be the sires, ^y duplicating the plat and detasseling 
the even rows in the duplicate, seed could be saved from 
every mother ear. (111. Agr. Exp. Sta., Bulls. 82 and 100.) 

94 



METHODS OF LAYING OUT A BREEDING-PLAT 95 

3. About 19G4 to 1906, Professor Williams, of Ohio, 
applied the " check row " system to the breeding-plat 
and developed the " ear remnant " plan. The " check 
row " was a composite planted for every sixth row. This 
was for the purpose of checking the uniformity of the land, 
as the breeder might unconsciously select for a breeding- 
plat a piece of land more fertile at one side than at the 
other. 

One difficulty found with the ear-to-row method in 
practice was that the best-yielding row might chance to be 
between two very, poor jdelders, so that seed ears saved 
from this row would be partly crossed with the poor- 
yielding rows on each side. In order to meet this diffi- 
culty, the plan was adopted of planting only a part of 
each ear, sufficient to determine the kind of progeny it 
would develop, and the remainder of the ear was kept. 
The next season, remnants of only the best ears would be 
planted in parallel rows and a part detasseled ; but with 
the poor-yielding rows eliminated, all the fertilization 
would come from desirable rows. (See Ohio Agr. Exp. 
Sta., Circ. 66 (1907) ; Amer. Breeder's Assoc, ///; 110.) 

HOW TO CONDUCT A BEEEDING-PLAT 

69. As there is considerable inquiry at present regarding 
methods of corn breeding, it seems best at this time to 
outline a plan which experience so far seems to recommend. 

Variety to use. — Select some variety that is well 
adapted to the region and is a good yielder. This is 
important, as one might spend years in working on a poor 
variety, and in the end have nothing better than the best 
variety already existing. It may be well to do some pre- 
liminary variety testing. 



96 CORN CROPS 

Selecting the ears. — If yield is to be the principal object 
of selection, it will not be necessary to hold closely to some 
one type of ear. In fact, since we do not know definitely 
what particular type of ear in a variety may do best in a 
new locality, it would seem wise to select several types, 
the main consideration being that the ears are sound and 
well matured. 

Number of ears to select as foundation stock. — Excep- 
tional ears are not common, there being probably not more 
than one in every fifty to one hundred ears. Therefore, 
if one starts with only a small number of ears, twenty- 
five to fifty, he may not find a single exceptional yielder 
in the lot. Not less than one hundred ears, and pref- 
erably two hundred should be tried out in the prelimi- 
nary trial. 

The test plat. — Great care should be exercised in pro- 
curing a uniform piece of land for the test plat, as every- 
thing depends on being able to compare in an accurate 
way the yields of the different ears. The land should not 
be exceptionally rich, but only of the average fertility of 
the region. If the land can be plowed twice — say fall- 
plowed, and then backset in the spring — and disked sev- 
eral times, this will do much toward equalizing conditions. 

Size of plat. — Half an ear will plant a row 16 to 20 
rods in length. However, there will be less error if the 
rows are duplicated, and it is best to plant two rows 8 rods 
long from each ear. One hundred ears will make two 
hundred plats 8 rods long. This will take a piece of land 
32 by 11 rods or 16 by 22 rods ; or two test plats one-half 
this size on different parts of the farm may be used, dupli- 
cating the experiment in each. 

Check plats. — No matter how carefully the land is 
selected, it may lack uniformity; for this reason, check 



METHODS OF LAYING OUT A BREEDING-PLAT 97 

plats should be planted with a uniform lot of corn. It 
has been found very satisfactory in practice to make 
every fifth plat a check. The simplest way is to make a 
check of every plat that is a multiple of 5, as 5, 10, 15, and 
so on. 

Planting the ears. — The land should first be laid off 
by a marker into checks 3 feet 8 inches apart. The 
planting must be done by hand. Carry the ear, and shell 
off the grains as needed. It is best to plant four grains 
in a hill; then, when the corn is 6 inches high, thin it 
down to two stalks. This "will give a perfect stand. 
Every precaution should be used to secure uniform con- 
ditions in each plat; otherwise the experiment would be 
a waste of time, as the results would not mean anything. 

Cultivation. — Ordinary cultivation should be followed, 
care being taken that none of the rows are unduly injured. 

Taking notes. — Some breeders prefer to keep extensive 
descriptive notes for their own information, but for 
practical results, very little note-taking is necessary 
other than accurately to secure comparable yields. If 
the breeder is selecting for some particular quality, such 
as earliness, height of ear, angle of ear, and the like, he 
must take notes on these points. Also, taking a set of 
notes on each individual row furnishes the very best train- 
ing possible in close observation; and as a man cannot 
know too much about the corn plant in order to be a 
successful breeder, it will usually pay him well to keep as 
complete a record as possible. 

70. Harvesting. — When corn first ripens it contains 
25 to 30 per cent of water, but it slowly dries out to about 
15 per cent. In the breeding-plats some rows ripen and 
dry out sooner than others ; hence, the weights will not 
be comparable until apll are equally dry. For this reason 



98 CORN CROPS 

it is best to leave the breeding-plats in the field for six 
to eight weeks after ripening, or until about December 1. 
Any very late-maturing or slow-maturing rows should be 
noted and discarded at harvest, as a type that will not 
mature well is undesirable. 

A very good method of harvesting the plats is to divide 
a wagon box into two to four compartments. Husk a 
plat into each compartment. At the end of the rows, 
have a platform scale with a box large enough to hold 
the corn from one plat. Scoop the corn into this box, 
and as each plat is weighed, dump the corn at the end of 
the row, leaving the plat stake with each pile. 

Leave the corn in these piles until all plats are husked, 
then mark the piles from high-yielding rows. A careful 
examination can now be made of these piles in order to 
note whether any seem immature, low in vitality, or other- 
wise undesirable. About one-fourth of the best plats 
should be noted, that is, 20 to 25 out of 100 piles. From 
these, seed for the general crop may be selected for the 
nest year. 

The breeder still has one-half or more of the original 
ears from which the crop has grown. It is from these 
that he will build up his improved strains of corn. 

71. The second year's work. — The best twenty or 
twenty-five original ears having been located, the rem- 
nants of these are again planted in separate rows the second 
year. The reason for so large a number of the remnants 
being again planted is because the degree of error may be 
so large — due to the fact that one season may favor a 
certain type — that we cannot determine exactly, the first 
year, just which are the best two or three for all seasons. 
When the second year's results are obtained, we may decide 
which to choose on the basis of t\W3 years' record. The 



METHODS OF LAYING OUT A BREEDING-PLAT 99 

seed from the best two or three rows may now be used 
as foundation stock for a select strain of corn. When the 
original ears are large, there will be quite a remnant left 
even after testing two years. 

i2. Continuation of breeding, several plans. — After 
the second year, a choice of several plans may be 
followed : — 

1. Progeny of the best rows may be planted in a mul- 
tiplying field for seed. Seed of this kind has given an 
increase of 9 bushels per acre (p. 92, Class II). It prob- 
ably will not maintain its increased yield more than a 
few years without continued selection. 

2. Ears may be selected from the best-yielding rows and 
the ear-row selection work continued. In this case it 
would be best to use some plan for preventing close breed- 
ing. Detassel every alternate ear-row plat having un- 
related rows on each side. Save seed ears only from the 
best detasseled plats. This may be continued indefinitely, 
but it is probable that new ear-row plats should be started 
every two or three years for the purpose of securing new 
ears to be used as sire rows in the breeding block, thus 
giving a new stimulus through crossing. No work has 
yet been reported to show just what results are to be 
expected. 

3. The original ear remnants may be used in a breed- 
ing block. Williams advocates this, using the best one 
or two ears for sires and detasseling the rest. The ear- 
row test is to be continued each year, securing ears from 
various sources, as the breeding-plat, general crop, or 
registered ears from other breeders. Each year the best 
remnants will be saved to be crossed the following year 
and passed into the multiplying plat the following season. 

4. As the best-yielding ears may be hybrids of the 



100 CORN CROPS 

" elementary strains that nick well/' plants from the best 
ear remnants could be used for inbreeding for the purpose 
of securing pure strains. There is more chance of secur- 
ing strains that will cross well from these ears than when 
plants are taken at random. After pure strains had been 
secured that would cross to advantage as determined by 
experiment, these strains would be grown from yesir to 
year in isolated fields and used each year to produce 
first-generation hybrid seed. 

SUMMARY 

73. No fixed relation has been found between type and 
yield. The largest well-matured ears growing under 
normal conditions of soil and stand should be used for 
seed. Large ears with a medium depth of grain usually 
mature better than large ears with a very deep grain. 

Mass selection and pedigree selection will ultimately 
give similar results when visible characters are chosen, 
as height of ear or shape of ear ; but with invisible char- 
acters, as abilit}^ to yield, results are not so sure with 
mass as with pedigree selection, and at best they will 
come slowly. 

Pedigree selection involves the testing of each ear sepa- 
rately for yield, by planting a part. The remnants of 
best ears may be used directly as a foundation stock and 
the progeny may be continued in some system of ear-to- 
row selection. The very highest values will be secured 
by systematic crossing of the best strains. 



CHAPTER X 
RESULTS WITH HYBRIDIZATION 

Perhaps no cultivated plant has yielded so many inter- 
esting results of both practical and purely scientific value, 
as a result of hybridization, as the corn plant. Corn freely 
hybridizes, thus offering many opportunities for the selec- 
tion of natural hybrids. The plant is so easily manipu- 
lated in artificial crossing, that almost any one may succeed 
with it who would fail with other crops. Not only have 
important results been secured bearing on the improve- 
ment of yield in quality of corn, but also interesting scien- 
tific data relating to the herechtary laws governing plants 
and animals, have also been secured with corn. 

DEGREES OF RELATIONSHIP 

74. When pollen of a maize plant falls from its own 
tassel on its own silk, this is called " inbreeding." When 
pollen from one variety is used to fertilize another variety, 
it is called " broad breeding." There are several interme- 
diate grades of relationship, which may be summarized as 
follows : — 

1. Inbreeding (pollen from own tassel). 

2. Close breeding (pollen from sister plant, that is, 

plant from the same ear) . 

3. Narrow breeding (pollen from plants of the same 

variety) . 

101 




Fig. 29. — Chart showing possible degrees of relationship between corn 

plants. (See text.) 

102 



RESULTS WITH HYBRIDIZATION 



103 



4. Broad breeding (pollen from plants of a different 

variety) . 

5. Broad breeding (pollen from plants of a different 

group, as between flint and sweet corn). 



XENIA 



75. Cross a common dent corn on a sweet corn, using 
pollen from the former. When the ear is mature, instead 




Fig. 



30. — Method of covering tassel and ear for 
artificial pollination. 



of the kernels being wrinkled and translucent as in sweet 
corn, all of them will be smooth, resembling a dent corn. 



104 COBN CROPS 

This is called xenia, or " the immediate effect of pollen 
on the endosperm.'' The effect of xenia, however, is 
limited to the kernel, there being no apparent effect on 
the cob or on the stalk. 

In ordinary hybridization, onlj^ the germ is a hybrid and the 
endosperm surrounding is not affected. Xenia is accounted for 
by "double fecundation." I^?. single fertilization, only one 
of the two generative nuclei which are formed in the pollen tube 
is supposed to pass into the embryo sac and unite with the egg 
cell. In double fecundation both nuclei enter the egg sac, one 
fusing with the nucleus of the egg cell, and the other with the 
polar nuclei to form the embryo sac nucleus, the division of which 
gives rise to the endosperm. The endosperm would then be a 
hybrid and partake of the dominant chara^cters of the male 
parent. 

When only a part of the kernels show xenia, it means that 
double fertilization does not always take place. It is neces- 
sary that the germ cell be fertilized, but it appears at present 
that fertilization of the endosperm nucleus is incidental rather 
than necessary. 

Mendel's laws 

76. If crossed or hybrid kernels of dent and sweet corn 
be planted, they will produce ears having both dent and 
sweet corn kernels, with a ratio of three dent corn grains 
to one sweet corn grain. This is explained by assuming 
that the germ cells (pollen grains or ovaries) are either 
pure sweet corn or pure dent corn. 

When a plant is grown from a hybrid seed, then, one- 
half the pollen grains will represent pure sweet corn, and 
one-half pure dent corn, and the same with the ovaries. 
While the plants may be hybrid, the sexual elements re- 
main pure. In the process of fertilization a union produc- 
ing a hybrid (sweet X dent or dent X sweet) will occur 
twice as often as a pure dent (dent X dent) or a pure 
sweet (sweet X sweet). 



RESULTS WITH HYBRIDIZATION 105 

All the hybrid kernels resemble the dent corn kernels, 
so we apparently have three dent kernels to one sweet 
kernel on each self-fertilized hybrid ear. If the seed of 
one of these hybrid ears be sown, we apparently harvest 
three starchy ears to one sweet ear, as follows : — 



Germ Cells 


Character op Progeny 


Starchy x starchy 


Starchy 


Starchy x sweet 


Starchy 


Sweet X starchy 


Starchy 


Sweet X sweet 


Sweet 



DOMINANT AND KECESSIVE CHARACTERS 

77. In the above example, every hybrid ear has a starch 
grain and cannot be distinguished, on inspection, from a 
pure starchy type. Starchiness in this case is dominant 
over the sweet corn grain ; or, in an ear that is a hybrid 
of dent corn and sweet corn, instead of the dent and 
sweet corn types blending, thus giving an intermediate, 
the dent completely dominates. In this case the sweet 
corn is recessive. By experiment this quality has been 
determined for many characters of maize, the following 
being typical examples : — 



Red colors of cobs, stem, or husks dominant over green. 
Starch endosperm dominant over sweet endosperm. 
Yellow endosperm dominant over white endosperm. 
Blue aleurone dominant over colorless aleurone. 
Red pericarp dominant over colorless pericarp. 
Podded kernels dominant over naked kernels. 




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RESULTS WITH HYBRIDIZATION 107 



HYBRIDIZATION, EFFECT ON GROWTH 

78. Two very distinct results follow cross-fertilization 
in maize : first, certain hereditary characters from both 
parents are bound up in the embryo, to be carried over 
into the next generation ; second, a stimulus to vegetative 
growth is given, to be carried over into the hybrid genera- 
tion. The carrying over of hereditary characters has 
already been discussed under the topics " Xenia " and 
" Mendel's Law," and the principal discussion here will 
deal with the second effect of hybridization. 

SELF-FERTILIZATION 

79. If a maize plant is self-fertiUzed (own pollen on own 
silk), and this process is repeated for two or three genera- 
tions, and selected seeds are used, there may gradually 
be produced a '' pure t3^pe." That is, the wide range of 
variation is decreased each year, until the progeny of the 
individual, being self-fertilized, are all of one type. For 
example, ShuU self-fertiHzed corn plants of a white dent 
variety for five years and, as a result, secured strains that 
came true with 8, 10, or 12 rows, and so on up to 24-rowed 
ears. The pure strains differed also in other respects, 
but all the plants of a given pure strain were very similar. 
At the Nebraska Agricultural Experiment Station ten 
very distinct strains were isolated from Hogue's Yellow 
Dent, by inbreeding for three years. 

The inbred strains also become dwarfish in size, have a 
high percentage of barren plants, and sometimes become 
entirely sterile. 

The decrease in yield is illustrated by the following data 
from ShuU. Two strains, designated as A and B, which 



108 



CORN CHOPS 



had been inbred for five years and appeared to be pure 
strains, were compared with the original corn. The table 
also summarizes results with four strains of Learning 
inbred by East, and a combination of several strains of 
Hogue's Dent inbred by Montgomery : — 



TABLE XVI 



Experimenter 


Description of 
Seed 


Yield 
PER Acre 

OF 

Original 
Strain 
Bushels 


Yield per Acre of Inbred 
Strain. (Number of Years 
Inbred at Head of Column) 








1st 


2d 


3d 


4th 


5th 


ShuUi . . . 

East 2. . . . 
Montgomery ^ . 


Pure strain A 
Pure strain B 


79.4 
79.4 
88 
40.7 


50.1 


59.9 


49.0 
9.9 


51.8 


14.2 
12.1 



1 Ann. Rpt. Amer. Breeders Assoc, Vol. VI: 63-72. 1909. 

2 Conn. Agr. Exp. Sta., Bui. 168. 1911. 

3 Nebr. Agr. Exp. Sta. Ann. Rpt. 1912 : 183. 

It is evident from these data that the immediate effect 
of self-fertilization is to reduce the yield, the greatest 
reduction taking place the first year. 

The amount of decrease seems to differ with varieties, 
or even with strains of the same variety. In general, 
inbreeding will decrease yield to about one-haK the first 
year. Continuing the inbreeding will in some cases 
reduce the yield to one-fourth the original yield, while 
in other cases, inbred strains become entirely sterile. 
Present experiments indicate that the yield is reduced 
until the strain becomes a '' pure strain," after which 
inbreeding has no further effect in decreasing yield. 

Very often abnormal types appear in inbred strains. 



BESULTS WITH HYBRIDIZATION 



109 




Fig. 32. — The effect of three degrees of relationship in crossing is here 
illustrated. Nos. 3 and 4 are pure strains inbred for three years. No. 
2 from a close fertilized seed-stock, the plants each year fertilized from 
sister plants from the same ear. No. 1 is from a seed-stock, cross fer- 
tilized for three years. 



PURE STRAINS, OR BIOTYPES 

80. Doctor Shull first presented the idea that a corn- 
field is to be considered more or less a mixture of pure types 
(biotypes) and that most of the plants in a field are more 
or less complex hybrids. By inbreeding, some of the 
original pure types might be isolated. In other words, a 
cornfield is a complex mixture of types, and inbreeding 
gives much the same result as does a chemical analysis with 
a complex compound — resolves it into its original elements. 





Fig. 33. — Pure types such as may be originated from a single variety or ear 
of corn by inbreeding. They are reduced in size, but each type comes true. 

110 



RESULTS WITH HYBRIDIZATION 



111 



CROSSING BIOTYPES 

81. However, these "elemental strains" are low in yield, 
but are stimulated to yield by hybridizing. The effect 
of hybridizing as a stimulus is shown in the following 
table : — 

TABLE XVII 



Experimenter 


Description of 
Seed 


Yield per 
Acre of 

Pure 
Strains 
Bushels 


First- YEAR Yield 

per Acre of 

Cross of Pure 

Strains 

Bushels 


Second-year 
Yield per Acre 
OF Progeny from 

Hybrid Seed 
Bushels 


Shull . . 
East . . 


J Pure type A 
[Pure type B 

Learning 
No. 12 

Learning 
I No. 9 


14.21 
12.1] 

35.4 

23.3 


79.8 
110.2 


69.5 

98.4 



The corn is at once restored to full vigor by hybridizing. 
The yield appears to decrease somewhat the second 
year, probably because a certain percentage of the plants 
have returned to a pure-type (homozygous) state. 

Under natural conditions there is a certain percentage 
of both inbreeding and close breeding. This has led to 
the suggestion that means should be used to insure that 
all seed used is first-generation hybrid. This can be 
accomplished by alternating rows of pure strains and 
detasseling every alternate row, saving seed from the 
detasseled rows. 

CROSSING VARIETIES 

82. Several investigations have shown an increase from 
the use of first-generation hybrid seed, when two varieties 
have been crossed. The following table, summarized from 



112 



COBN CROPS 



Morrow and Gardner's experiments in 1892 at the Illi- 
nois Agricultural Experiment Station, illustrates : ^ — 

TABLE XVIII 



Variety 



Burr's White . . . 
Cranberry .... 

.Average . . . 

Cross .... 

Burr's White . . . 
Helm's Improved 

Average . . . 

Cross .... 

Leaming .... 
Golden Beauty . . 

Average . . . 

Cross . . . „ 

Champion White Pearl 
Leaming .... 
Average . . » 
Cross .... 

Burr's White . . . 
Edmonds .... 

Average . 

Cross .... 



Bushels of 
Air-dry Corn 



64.2 
6L6 
62.9 
67.1 

64.2 
79.2 
71.7 
73.1 

73.6 
65.1 
69.3 

86.2 

60.6 
73.6 
67.1 
76.2 

64.2 

58.4 
61.3 

78.5 



The average yield of hybrids in the five tests v^as 9.7 
bushels above the average of the parents and 4.5 bushels 
above the average of the highest parents. It is also 
shown, by this and other data, that certain crosses give 



1 111. Agr. Exp. Sta., Bui. 25. 1902. 



RESULTS WITH HYBRIDIZATION 



118 



greater increases than do others. Hartley has found that, 
while certain crosses give an increase, others give a 
decrease, and in some cases the cross is almost sterile. 
Probably those varieties that have been longest selected 












Fig. 34. — A breeding plat where many tassels and ears are covered with 
paper bags, for artificial pollination. 



as to type, and therefore are the nearest to a pure (homo- 
zygous) state, will respond most readily to crossing. 

83. ShuU has found that when a variety has been 
resolved, by inbreeding, into pure strains, certain of these 
pure strains when crossed give yields superior to the yield 
of the original corn, while other combinations give poor 
yields. He suggests that the maximum yields will be 
secured by first reducing a variety to its elemental strains, 
and then producing hybrid seed each year from only 



114 



COBN CROPS 



those strains that give maximum results. This would 
necessitate maintaining the pure strains each in a separate 
field from year to year, and having another seed field where 




Fig. 35. — Pure types as developed by inbreeding. No. 11 produces 
many tillers, and was reddish in color. No. 12 was free from tillers. 



they would be planted in alternate rows. One strain 
would be detasseled in this seed patch, thus giving each 
year a stock of hybrid seed. 



RESULTS WITH HYBRIDIZATION 115 

ISOLATING HIGH-YIELDING BIOTYPES 

84. Evidence at present indicates that high-yielding 
ears, found by the ear-row method of testing, are in many 
cases natural hybrids of high-yielding biotypes. Thus 
by securing high-yielding ear remnants as foundation 
stock, they might be inbred until pure types were ob- 
tained. There is greater probability of securing biotypes 
that would combine to advantage from this stock than if 
a chance stock were used as a beginning. 

SUMMARY 

85. Fertilization is the result of the union of the con- 
tents of a pollen grain with the egg cell of an ovary. 
Xenia is the immediate effect of pollen in changing the 
character of the maize grain. 

Mendel's law refers to the phenomenon of transmitting 
characters in toto, without blending, as in the case of 
dent and sweet corn when crossed. 

Hybridization usually gives a decided stimulus to growth, 
while self-fertilization has the opposite effect. Continuous 
self-fertilization may reduce yield to one-fourth or less 
of the original yield, but the yield is fully restored in the 
first generation hybrids. A field of corn appears to be a 
miscellaneous mixture of biotypes, naturally not very 
productive, but stimulated to the highest degree of pro- 
ductivity by hybridizing. Certain biotypes hybridize 
to better advantage than do others. 

References on xenia : — 
Webber, H. J. (1900.) Xenia. U. S. Dept. Agr., Div. Veg. 

Physiol, and Path., Bui. 22. 
GuiGNARD, L. (1901.) La Double Fecundation dans le Mais. 

Journ. Bot. [Paris], 15 : 1-14. No. 2. 



116 COBN CROPS 

References on inheritance in maize : — 
CoRRENS, C. (1901.) Bastarde zTvischen Maisrassen mit Beson- 

derer Berucksichtigung der Xenien. Bibliotheca Bot., 55: 

1-161. 
Lock, R. H. (1906.) Studies in Plant Breeding in the Tropics, 

111. Ann. Roy. Bot. Gard. Peradeniya, 3 : 95-184. 
East, E. M. A Note Concerning Inheritance in Sweet Corn. 

Science, N. S. 29 : 465-467. 
1911. Inheritance in Maize. Conn. Agr. Exp. Sta., Bui. 167. 
Emerson, R. A. (1911.) Genetic Correlations and Spurious 

Allelomorphism in Maize. 24th Ann. Rpt. Nebr. Agr. 

Exp. Sta. 

References on crossing varieties : — 

Collins, G. W. (1909.) The Importance of Broad Breeding in 
Corn. U. S. Dept. Agr., Bur. Plant Indus., Bui. 141. 

(1910.) The Value of First-Generation Hybrids in Corn. U.S. 
Dept. Agr., Bur. Plant Indus., Bui. 191. 

Increased Yields of Corn from Hybrid Seed. U. S. Dept. Agr. 
Yearbook 1910 : 319-328. 

Morrow, G. E., and Gardner, F. D. (1892.) Field Experi- 
ments with Corn. 111. Agr. Exp. Sta., Bui. 25: 173-203. 

Kellerman, W. a., and Swingle, W. T. Ann. Rpt. Kans. 
Agr. Exp. Sta., No. 1 : 316-337, 1889; No. 2: 288-355, 
1890 ; and Kans. Agr. Exp. Sta., Bui. 27 : 139-158. (1891.) 

East, E. M. Conn. Agr. Exp. Sta., Bui. 167. 1911. 

Hartley, C. P., and associates. Cross-breeding Corn. U. S. 
Dept. Agr., Bur. Plant Indus., Bui. 218. 



CHAPTER XI 
ACCLIMATION AND YIELD 

A BOTANICAL survey of the United States shows large, 
well-defined regions, each with a characteristic native 
flora. 

86. Considering the great length of time that native 
vegetation has had -in which to adjust itself, these various 




Fig. 36. — i'iau±c vegetation in the " bliort grasa " region. The natural 
vegetation indicates a very great difference in natural climate. 

regions must indicate different environmental conditions, 
or else we should have a homogenous native vegetation 
throughout the country. Those regions covered with a 
forest vegetation must differ in environment (soil or cli- 
mate) from a prairie region. There are various kinds of 
forest regions, as evergreen and deciduous ; while in the 

117 



118 



CORN CROPS 



prairies we have, along the Missouri River, a tall vegeta- 
tion of grass and other plants, waist-high to a man, in 




Fig. 37. — Prairie vegetation in humid region. Compare with Fig. 36. 
There must be qmte a marked difference in the types of corn adapted 
to these two regions. 

marked contrast to the " short grass " country three hun- 
dred miles westward. 

Even within a State distinct floral zones can often be 
identified, as in Nebraska, for example, where six zones 
are recognized, each with a characteristic vegetation. 



EFFECT OF ENVIRONMENT ON THE CORN PLANT 

87. It has long been observed that each region would 
have a distinct type of corn plant. In northern regions 
the plant is leafy with the ear borne very low; in dry 
regions the plant is stocky, with a high proportion of ear 
and often with scant leaf ; while in southern regions the 



ACCLIMATION AND YIELD 



119 



plants are tall and have a low proportion of ear to 
stalk. 



EFFECT OF PREVIOUS ENVIRONMENT ON YIELD 

88. The marked effect of a change in environment on 
yield of grain has often been noted, the change usually 
decreasing the yield at first. At the Arkansas station/ 
233 samples of corn were collected from various States 
and grown in comparison for two years. 

In 155 trials with seven varieties, the highest yield was 

secured with seed grown between the thirty-fifth and 

thirty-eighth parallels of latitude, rather than either 

north or south of this region, this being the latitude of the 

Arkansas station. 

TABLE XIX 

Table showing the Yield of Corn from Seed of Differ- 
ent Sources at the Arkansas Agricultural Experi- 
ment Station 



Namks of Varieties 


Num- 
ber OF 
Tests 


Seed grown 

North of 38th 

Parallel of 

Latitude 


Seed grown 
between 35th 

AND 3Sth 
Parallels of 

Latitude 


Seed grown 

South of 35th 

Parallel of 

Latitude 




Average for 2 , 
Years 


Average for 2 
Years 


Average for 2 
Years 


Learning . . . 
Golden Beauty . 
Hickory King . 
Golden Dent 
Champion White 
Pearl . . . 
Early Mastodon 
White Dent . . 


21 
20 
23 
26 

11 
16 

38 


20.98 
32.81 
24.855 
21.52 

22.62 
33.54 
24.175 


26.20 
45.775 
31.81 
25.00 

32.00 
33.75 
34.695 


17.20 
50.475 
29.10 
25.30 

30.10 
33.45 
34.775 


Average Total 


155 


25.785 


32.47 


31.485 



1 Newman, C. L. (1899.) Ark. Agr. Exp. Sta., BuL 59. 



120 



CORN CROPS 



At the Nebraska Agricultural Experiment Station six 
leading varieties of corn were compared for two and three 
years, the seed in one case being native-grown and in the 
other from Iowa or Illinois. Results were as follows : — 

TABLE XX 

Table showing Yield of Corn from Acclimated Seed and 
Seed from Other Regions, at the Nebraska Agricultu- 
ral Experiment Station 



Name and Places of Origin 


1903 


1904 


1905 


Average 


Differ- 
ence 


S,.ern,ne{^^^ ■ ; 




70.0 


76.1 


73.0 






65.1 


63.4 


64.2 


8.8 


^^Mn^f"" : : : 




95.2 


69.8 


82.5 






76.6 


72.3 


74.4 


8.1 


Snowflake Nebraska. . . 


73.7 


84.8 


74.5 


77.7 




White Iowa . . . . 


68.7 


72.8 


67.1 


69.5 


8.2 


Boone County | Nebraska . 




76.2 




76.2 




White I Illinois . 




68.9 




68.9 


7.3 


Early Yellow f Nebraska 


68.1 


67.9 


75.1 


70.3 




Rose 1 Iowa . 


62.1 


76.9 


63.5 


67.5 


2.8 


Reid's Yellow Nebraska . 




83.8 


64.2 


73.7 




Dent Illinois . 




82.8 


60.8 


71.8 


1.9 


Average 










6.2 



In every case the native seed gave best results. 

In another experiment conducted with farmers in western 
Nebraska, it was found that native-grown seed gave better 
results than seed grown in eastern Nebraska.^ Rainfall in 
the western part of the State is very low, averaging about 
18 inches annually, while the rainfall is about 30 inches 
in eastern Nebraska. To succeed in the West corn must 
be adapted to drought resistance. 



1 Nebr. Agr. Exp. Sta., Bui. 126. 1912. 



ACCLIMATION AND YIELD 



121 



TABLE XXI 

Table showing Comparative Yield of Native- and Im- 
ported-seed corn in western nebraska in bushels 
PER Acre 





Year 


Varieties not 

Native (mostly 

FROM Eastern 

Nebraska) 


Native Varieties 


Difference 


1908 .... 

1909 .... 


24.1 
20.9 


30.5 

25.4 


6.4 
4.5 


Average . . . 


22.5 


27.9 


5.4 





ADAPTATION OF THE SOIL 

89. The climatic and soil requirements of corn have been 
stated in Section II. The climate cannot be controlled 
or modified in a marked degree, hence corn production 
is limited by climate to those regions w^here the natural 
rainfall, temperature, and like conditions are favorable to a 
profitable production. 

The soil, however, is subject to treatment, and almost 
every soil can be brought to a high degree of productive- 
ness by proper management. The subject of soil manage- 
ment is so fully treated in special t^xts on this topic, that 
it is not necessary to take up the matter in detail here. 

From a study of corn soils as classified according to 
productiveness, it is apparent that a large proportion of 
the soil likely to be cultivated in corn may be grouped in 
two classes : first, soils that were once productive but 
are now more or less deplete by 50 to 200 years cropping ; 
and second, soils that never were productive. In both 
cases the important factors to be modified can be grouped 
under three general heads, as follows : (1) organic matter, 
(2) mineral matter, (3) water. 



CHAPTER XII 

CROPPING SYSTEM IN RELATION TO MAIN- 
TAINING THE YIELD OF CORN 

The discussion so far, on the adaptation of soil for com 
growing, brings out the fact that the constant growing 
of corn involves the development of a cropping system 
by which, with the least cost, the organic matter can be 
maintained and the most profitable use made of any 
fertilizing material that it may be necessary to add. 

90. Cropping systems in the United States undergo evo- 
lution from the time when new land is opened up to the 
time when it reaches a permanent agricultural basis. 

When new land is first brought under cultivation, grain 
farming is the general custom. Often a single crop is 
cultivated, as wheat in the Northwest. In a few years 
the single crop becomes unprofitable, due to the coming of 
insect pests or plant diseases, or to the decreasing avail- 
ability of some mineral element in the soil. Then cul- 
tivated crops are introduced to alternate with the small 
grain. 

In many regions of the Corn Belt, corn was continu- 
ously raised until it became necessary to introduce small 
grain culture. After a time, however, the continuous 
rotation of grain crops alone no longer gave paying crops. 
In general, this appears to be due to : — 

1. Exhaustion of actual organic matter resulting in 
(a) Decrease in availability of some necessary 

element as phosphorus, or 
(6) Poor physical condition of the soil. 
122 



CR OP PING S YS TEM 128 

2. Exhaustion of some necessary element, usually lime, 
nitrogen, phosphorus, or potassium. 

RESTORING PRODUCTION 

91. When low production is due to the exhaustion of 
organic matter, then any cheap system of restoring that 
matter, as plowing under a green manure crop, will usually 
restore production in a measure. One effect of this de- 
caying organic matter is the reaction on the minerals of the 
soil, thus increasing solubility. 

The physical effect is to make the soil more loamy in 
character by increasing granulation of clay, on the one 
hand, and on the other hand, in the case of sandy soils, 
binding the particles together. In this case no new 
supply of plant food is added to the soil, as the organic 
matter is grown on the land and only adds to the soil the 
carbon compounds taken from the air. Adding organic 
matter from an outside source, in addition to the above, 
also adds its own supply of elements. 

When a certain element has been exhausted from the 
soil, that element may be added. 

Nitrogen may be added in three ways : (1) by growing 
leguminous crops ; (2) by adding organic matter from an 
outside source ; (3) by adding nitrogen salts. 

Phosphorus, potassium, and lime can be restored in two 
ways : (1) by adding organic matter from an outside 
source ; (2) by adding salts of phosphorus, potassium, or 
lime. 

Aside from a proper system of drainage where needed, 
the whole problem of devising a cropping system, includ- 
ing the application of fertilizers for maintenance or in- 
crease of production, is involved in the above statements. 



124 



CORN CROPS 



Cropping systems may then be classed as : — 

(1) Those that decrease productivity. 

(2) Those that maintain productivity. 

(3) Those that increase productivity (or in most cases 
merely restore it). 

Exj>eriments demonstrating the above cases have been 
made in a number of States where corn was used as one of 
the crops in the system. 



MAINTAINING PRODUCTION 

92. Results are reported from the Illinois station/ where 
corn has been grown in three systems of cropping, for 13 
years in one case and for 29 years in the other. 

TABLE XXII 

Illinois Corn Yields where Three Systems of Cropping 
ARE Compared. Average Yield for Last Three Years 





Crop Years 


Crop System 


13-YEAR 

Experiments 
Bushels 


29-YEAR 

Experiments 
Bushels 


1905-6-7 . . 
1903-5-7 . . 
1901-4-7 . . 


Corn every year 
Corn and oats 
Corn, oats, clover 


35 
62 
66 


27 
46 
58 



The land on which these experiments were conducted 
originally produced more than 70 bushels per acre. There 
has been some decrease in yield in all cases, but less de- 
crease where rotation was practiced. Yield cannot be 
maintained by rotation alone where the crops are removed. 

In a second series of plots a corn-oats-clover rotation was 
practiced, where all was returned to the land except the 
grain and clover seed harvested. In one case, the straw, 

iJU. Agr. Exp. Sta., Bui. 125 : 324. 1908. 



CROPPING SYSTEM 



125 



cornstalks, and clover were all plowed under, and this 
system was designated as " grain farming " since no live 
stock to produce manure was needed. 



HBbHCHBMKSW^^mmJ^^SSBBP^^muh'' B^^i ^l^^T^^^^^^^^twL^ 




^^■-'"^"^^^^^^^^^yr^^ 



Fig. 38. — Good land, continuously cropped with grain, until it is in an 
unproductive state. 

In a second series, designated '^ive-stock farming," the 
crops have been removed but equivalent manure returned. 







Grain 


Live-stock 






Farming 




Crop Years 


Special Treatment 


Legumes ^ 


Manure 2 






Bushels 


Bushels 


1905-6-7 . . 


None 


69 


81 


1905-6-7 . . 


Lime 


72 


85 


1905-6-7 . . 


Lime, phosphorus 


90 


93 


1905-6-7 . . 


Lime, phosphorus, 








potassium 


94 


96 



1 Legume catch-crops and crop residues. 

2 Manure applied in proportion to previous crop yields. 

Growing legumes and returning all residues has main- 
tained yield, and when in the form of manure has increased 



126 



CORN CROPS 



yield. When additional minerals have been added, the 
crop production has been actually increased about 20 
per cent. 

At the Indiana station ^ five cropping systems have been 
compared for 20 years, with and without commercial 
fertilizers. Without giving details, the following table 
shows clearly enough the comparative effect of different 
cropping systems on the maintenance of production. 

TABLE XXIII 

Indiana Experiments, comparing Corn Yields at Begin- 
ning AND End of Twenty-year Period in Different 
Rotations 





Cropping Systems and Yields in Bushels per Acre 


Treatment 


I 

Continuous 
Corn 


II 

Corn and 

Wheat 


III 

Corn, Oats, 
Wheat- 
Clover 


IV 

Corn, Oats, 
Wheat, 
Clover- 
Grass 


V 

Corn-roots, 
Oats, 
Wheat, 
Clover- 
Grass 




Yields in 1889 when the Experiments were Begun 


Unfertilized . 
Fertilized 


61.1 
62.1 


50.0 
49.3 


54.6 
54.8 


54.2 . 
56.4 


58.4 
58.1 




Yields in 1909 after 20 Years' Cropping 


Unfertilized . 
Fertilized 


26.0 
39.9 


25.4 
47.3 


47.8 
59.1 


35.5 
65.5 


61.1 
73.1 



Unfertilized 
Fertilized 



Difference between 1889 and 1909 Yields, showing 
Effects of Rotations 



35.1 
■22.2 



24.6 
-2.0 



-6.8 
+ 4.3 



- 18.7 
+ 9.1 



+ 2.7 
+ 15.0 



1 Ind. Agr. Exp. Sta., Circ. 25. 1911. 



CROPPING SYSTEM 



127 



The Indiana results confirm the lUinois experiments, 
showing : (a) a rapid decrease for continuous grain culture ; 
(b) a maintenance of yield for longer period when a 
rotation including legumes and grass is included ; (c) an 




Fig. 39. — Compare with i^ig. 3s. The same kind of land near by, but 
properly managed to maintain productivity. (Minn. Exp. Sta.) 

actual increase in productivity when fertilizer is added. 
However, fertilizer did not maintain yield in a grain rotation. 



ROTATIONS FOR CORN GROWING 

93. The above tables suggest the type of rotations 
and fertilizer treatment for the Corn Belt. Other stations 
have suggested rotations including corn, as follows : ^ — 

" A rotation for dairy farms recommended by the New 
Jersey station consists of (1) field corn, seed to crimson 
clover in July or August ; (2) crimson clover followed by 

1 U. S. Dept. Agr., Farmers' Bui. lU-' H- 



128 COBN CROPS 

fodder corn, land seeded to winter rye ; (3) rye fodder, 
followed by oats and peas, seeded to red clover and 
timothy ; (4) hay. [Crimson clover is not hardy north of 
New Jersey. — Author.] 

" A three-year rotation for the South, recommended 
by the Louisiana station, is (1) corn ; (2) oats, followed by 
cowpeas; and (3) cotton. 

'* At the Delaware station a good rotation for a poor 
soil in bad condition was (1) sweet corn, crimson clover ; 
(2) cowpeas, winter oats ; and (3) red clover. A fertilizer 
was applied. The results reported indicate that it is 
better to have crops growing continuously upon the land, 
than to have it lying idle during a part of the growing 
season." 

Each farmer must work out the rotation system best 
adapted to his own situation, ])ut the general lines to fol- 
low are indicated in the foregoing discussion. 



CHAPTER XIII 
ORGANIC MATTER FOR CORN LAND 

Organic matter has several important functions in the 
soil : (1) As a direct source of food supply. Decaying 
vegetable and animal matter contains all the essential food 
elements of plants. (2) As a means of freeing unavailable 
plant food elements in the soil. The organic acids given 
off by decaying organic matter act directly on the elements 
of the soil, in bringing them into solution. (3) The phys- 
ical condition of the soil is affected in a remarkable degree 
by the presence of even a small percentage of organic 
matter. Note the effect on a clay soil when a few loads 
of manure are applied to an acre of land. The organic 
matter improves the granulation and increases the water- 
holding capacity to some extent. Aeration is also im- 
proved. (4) A very important effect is to improve the 
soil as a medium for the growth of soil bacteria and fungi, 
which in turn become a source of organic matter to the 
soil. (5) Nitrogen-fixing bacteria are favored by abundant 
organic matter, if sufficient lime be present. 

Considering the fact that corn, in common with all 
cereals, must be grown without the extensive use of com- 
mercial forms of fertilizer, maintaining the supply of organic 
matter in the soil becomes the most important single consid- 
eration in extensive corn-growing regions. 

94. Good corn soils are rich in organic matter. Two of 
the best corn soils in the Central States are Miami black 
K 129 



130 



CORN CROPS 



clay loam and Wabash silt loam, the organic matter of 
which, according to Lyon and Fippin/ is as follows : — 



Soil 0-7 Inches 

Per Cent 
Organic Matter 



Miami black clay loam 
Av. 12 samples . 

Wabash silt loam 

Av. 11 samples . 




Subsoil 7-40 Inches 

Per Cent 

Organic Matter 



2.50 
1.30 



Of all the cereals corn is the best crop to grow first, 
after a heavy application of manure or the plowing under 
of organic matter, as a clover sod or green manure crop. 
It is well adapted to utilize the rather large store of 
nitrogen likely to become available at such time. Be- 
cause corn does well following the plowing under of coarse 
organic matter, it is sometimes called a " coarse feeder " ; 
while wheat, requiring a more advanced stage of decom- 
position, is termed a " delicate feeder." 

FARMYARD MANURE FOR CORN 

95. It has been demonstrated that lime, under certain 
conditions, applied to the land gave profitable increases ; 
in certain other cases commercial fertilizers have been 
profitable ; but farmyard manure, wherever used, has 
usually given profitable returns. It appears at present, 
however, that for a large share of the corn-growing area 
farmers are not justified in keeping sufficient live stock 
in their farming systems to depend on manure as the 
principal means of maintaining production. It must be 



1 Lton and Fippin. Soils, p. 125. 



ORGANIC MATTER FOR CORN LAND 



131 



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132 CORN CROPS 

supplemented by plowing under organic matter, especially 
green crops, containing enough legume crops to maintain 
the nitrogen supply. 

Perhaps the best comparative idea of the value of farm- 
yard manure and fertilizers can be obtained by examining 
certain data secured at the Pennsylvania station in a 
twenty-five-year test, two experiments at the Ohio station 

— one for sixteen years and the other for thirteen years 

— a nine-year test at the Indiana station, a thirteen-year 
record at the Illinois station, and a single corn crop after 
timothy at the Cornell station. 

The foregoing table is a summary of the data secured at 
the Pennsylvania and Ohio stations. These are the best 
continuous records that we have in the older portion of 
the United States, where the use of manure and fertilizers 
is now becoming a matter of importance. 

The summary shows that land yielding, under a good 
rotation, an average of 35.4 bushels of corn per acre has 
been maintained at an average of 48.4 bushels for the corn 
crop by an average expenditure of $15.20 for commercial 
fertilizers (where a complete fertilizer was used) for each 
course of the rotation (average of four years). These 
complete fertilizers were fairly well mixed to meet the 
needs of the soils in each case. An average application of 
11 tons of manure every four years has maintained the 
yield of corn at 51.82 bushels. 

The second part of the table shows the average financial 
returns for all crops grown during the course of rotation. 
Eleven tons of manure shows a better average return than 
$15.20 worth of commercial fertilizer, and an average 
return of $2.46 per ton for the manure. The Illinois 
station received a return of $1.60 per ton and the Indiana 
station $1.50 per ton for manure. Both the latter stations 



ORGANIC MATTER FOR CORN LAND 



133 



are on newer land^ where as large increases are not yet to 

be expected as on old cultivated land. 

Again, the Ohio station ^ has shown that the value of 

manure may be increased by adding and composting a 

small amount of mineral fertilizer with it. The following 

table summarizes the data, showing a marked increase 

in the value of the manure where treated with mineral 

fertilizer. 

TABLE XXV 

Value of Barnyard Manure treated with 40 Pounds per 
Ton of Different Minerals. Applied to Crops in 
A Three-year Rotation of Corn, Wheat, and Hay at 
THE Rate of 8 Tons per Acre. Average for Fourteen 
Years 



Plats No. 


Amendment 
Used 


Cost of 
40 Pounds 

Cents 


Total Value 
of Increase in 
One Rotation 


Net Value op 

Increase per 

Ton of 

Manure 


2-3 .. . 
5-6 .. . 

8-9 .. . 
12-13 . . 
15-16 . . 


Floats 
Acid phos- 
phate 
Kainit 
Gypsum 
Untreated 


18 

30 

34 

12 




$33.51 

38.08 
29.28 
27.41 
23.44 


$4.01 

4.46 
3.32 
3.30 
2.93 



In this case, the mineral was mixed with the manure as it 
was removed from the barns. A part was appUed directly 
to the land in each case, and a part allowed to decay in the 
yards for about three months. The former method 
seemed to be the better. 



SUMMARY 



96. In the foregoing discussion on the theory of applying 
fertilizers and manures for raising cereals, it appears that 
the permanent maintenance of the soil in a productive 

1 Ohio Agr. Exp. Sta., Circ. 120 : 112. 1912. 



134 CORN CROPS 

state is the most fundamental problem in production. 
For cereal culture, the soil must be maintained at the 
lowest possible cost. The four principal elements to be 
given attention in most soils are (1) nitrogen, (2) phos- 
phorus, (3) potash, (4) lime. In addition, active organic 
matter must be present. 

These conditions are met in the most practical way by : 

(1) A rotation in which legumes furnish a large share of 
the nitrogen used by other crops in the rotation. Red 
clover is the legume in the corn-belt and northern states 
to be depended on as the principal source of nitrogen and 
organic matter in ordinary rotations. 

(2) Where manure is not available, practically all 
organic matter grown on the land, with the exception of 
threshed grain, should be plowed under. 

(3) In order to maintain the full supply of organic 
matter and nitrogen, it may be necessary to plow under the 
entire legume crop without harvesting. 

(4) Where live stock is kept, all manure made by feeding 
produce should be returned to the land in relatively light 
dressings. 

(5) The constant removal of grain will gradually reduce 
the phosphorus and potassium. This must be returned 
as commerical fertilizer. A part at least can be mixed 
with the manure and applied in this way. 

(6) Where fertilizer mixtures are applied to land, careful 
regard should be given to the needs of the land, and the 
fertilizer should be mixed to meet the particular needs in 
each case. 

(7) Where lime is required, it should be applied once 
every four to six years, the amount being determined by 
the needs of the land. 



CHAPTER XIV 



MINERAL MATTER FOR CORN LAND 



As pointed out heretofore (p. 42), about 1 per cent of 
the green weight or 5 per cent of the dry weight of corn is 
ash or mineral matter, taken directly from the soil. For 
the production of 50 bushels of corn the mineral ash found 
in composition would be as follows : — • 

TABLE XXVI 

Mineral and Nitrogen Requirements of a 50-bushel Corn 

Crop! 







Nitro- 
gen 


Phos- 
phorus 


Potas- 
sium 


Mag- 
nesium 


Cal- 
cium 


Sul- 
fur 


Total 
Min- 
eral 


Total 
Ash 


Ears (3500 
lb.) . . 

Stalks (3000 
lb.) . . 


50.0 
24.0 


8.50 
3.00 


9.50 
26.00 


3.85 

4.80 


.7 

10.4 


.14 

3.00 
3.14 


24.29 
64.40 


43.4 
69.5 


Total . 


74.0 


11.50 


35.50 


8.65 


11.1 


88.69 


112.9 





97. Soils in regard to mineral supplies may be classed as : 

1. Soils in which sufficient mineral matter in available 
form is present. 

2. Soils in which sufficient minerals are present, but one 
or more of those minerals are unavailable or available in 
very limited amounts. 

3. Soils in which one or more minerals are so deficient 
that even with good soil management a sufficient amount 
cannot be made available for a crop, the total supply 
being sufficient for only a few crops. 



1 Hopkins, C. G. 



Soil Fertility, pp. 154 and 603. 
135 



136 CORN CROPS 

The first class included most of the present Corn Belt 
States when the land was first broken up. Large crops 
were grown without soil amendments, but to-day the yield 
is limited on most of these soils by the lack in available 
form of one or more mineral elements. 

In the second class, chemical analysis may show the 
presence of enough minerals and nitrogen for fifty to 
one hundred crops, and yet the crop be Umited, as the 
minerals may become available only very slowly. This 
class includes a large share of the above-mentioned soils 
that have been farmed fifty to one hundred years or more. 
Decreased availability of minerals may be due to several 
causes, as deficiency in bases such as lime or magnesium, 
or more often insufficient organic matter in a state of 
active decomposition. The addition of lime or organic 
matter, or both, is the evident remedy in such cases. 

In other cases there is no practical way of making avail- 
able sufficient mineral elements for maximum crops, and 
mineral fertilizers must be added. In many soils there 
are other inhibiting factors to plant growth, even when 
mineral elements are abundant. This is especially true 
on poorly drained soils where toxic organic compounds 
are developed. 

In class 3 are included many of the sandy soils and soils 
subject to leaching, erosion, or derived from rocks that 
original^ lack some mineral in composition. It is doubt- 
ful whether corn culture can ever be profitably developed 
on land of this class. An example is the sandy soil of 
Long Island, where most of the mineral must be supplied. 
Often a ton or more per acre of high-grade fertihzer is 
used. On such land only crops returning a large gross 
income per acre, as potatoes, cabbage, or truck, can be 
grown with profit. 



MINERAL MATTER FOR CORN LAND 



137 



98. Hopkins^ believes it fair to " assume for a rough 
estimation that the equivalent of 2 per cent of the nitrogen, 
1 per cent of the phosphorus, and i of 1 per cent of the total 
potassium contained in the surface soil can be made avail- 
able during one season by practical methods of farming." 

The above statement is borne out by results in many of 
the prairie soils of Illinois. The amount of nitrogen, 
phosphorus, and potassium in the surface, and the amount 
available annually on the above basis, is shown by Hopkins 
to be as follows : — 

TABLE XXVII 

Fertility in Illinois Soils and Amount Annually Avail- 
able IN Pounds per Acre (roughly estimated) 





Average per Acre in 

Surface Soil 2 

(0-6| IN.) 


Annually Available 3 


Soil Type No. 








Total 
Nitrogen 


Total 
Phos- 
phorus 


Total 
Potas- 
sium 


Nitro- 
gen 


Phos- 
phorus 


Potas- 
sium 


330 
426 


Gray silt loam 
Brown silt 


2,880 


840 


24,940 


58 


8 


62 


520 


loam . . 
Black clay 


4,370 


1,170 


32,240 


87 


12 


81 


635 


loam . . 
Yellow silt 


6,760 


1,690 


29,770 


135 


17 


74 


1401 


loam . . 
Deep peat 


2,390 

34,880 


850 
1,960 


37,180 
2,930 


48 
9 


9 
20 


93 

7 


AmoL 


mt required for 


50-busl 


lel cor 


a crop 


74 


11.5 


35.5 



From the above typical examples, it appears that many 
of these soils do not meet the requirements of a 50-bushel 
corn crop in all the three elements considered. 

1 Hopkins, C. G., I.e., p. 107. 

^ Ibid., -p. 82. s Ibid., p. no. 



138 CORN cnops 

The problem of production on soils of this class is to 
increase availability through use of manures and organic 
matter, but in many cases the addition of some mineral 
supplement is now necessary. 

FERTILIZERS FOR CORN 

99. Theory of fertilizer dosage. — If a perfectly sterile 
sand were used as a medium for growing crops, and it were 
desired to add fertilizing material, the logical method 
would be to ascertain the relative amount of mineral 
constituents in the plant under culture and add the minerals 
in the same relative proportion. For example, the three 
principal mineral constituents in the corn crop is shown in 
Table XXVI to equal, in a 50-bushel corn crop, 74.0 pounds 
of nitrogen, 11.5 pounds of phosphorus (or 26.3 phosphoric 
acid), and 35.5 pounds of potassium (or 42.6 potash) ; 
or the ratio would be about 6:2: 3 for nitrogen, phos- 
phoric acid, and potash. 

If the amount of fertilizer applied were to equal the 
expected crop, then for a 50-bushel corn crop we should 
apply about the following formula : 

74 lb. nitrogen = 400 lb. sodium nitrate 
11.5 lb. phosphorus = 190 lb. acid phosphate 
35.5 lb. potassium = 85 lb. muriate of potash 

Fertilizer for corn would not, however, be applied to a 
sterile soil, but to a soil usually containing enough miner- 
als and nitrogen in an unavailable state for fifty to one 
thousand crops. Organic matter and lime, and thorough 
tillage, assist in making minerals available ; but after all 
reasonably good treatment has been given, some one or 
more elements may be found available only in such small 
amount that the crop is hmited. 



MINERAL MATTER FOR CORN LAND 



189 



The fertilizer applied should be planned to supply the 
needed element or elements, rather than all elements. 
Also, a certain element may be deficient a part of the season 
but more plentiful at some other period. This is true of 
nitrogen, which is often deficient in early spring, especially 
on heavy clay soils, but may be more abundant by mid- 
summer. 

The Ohio Agricultural Experiment Station reports an 
experiment in which fertilizers were applied in arbitrary 
quantities in comparison with plats on which " the three 
fertilizing elements, nitrogen, phosphorus, and potassium, 
are given in approximately the same ratio to each other 
in which they are found in the plant." ^ 

TABLE XXVIII 

Fertilizer Tests with Continuous Corn Culture at the 
Ohio Agricultural Experiment Station. Average for 
Sixteen Years, 1894-1909 



Plot 
No. 


Fertilizing Materials 
Pounds per Acre 


Yield 


Increase 


Grain 
Bushels 


Stover 
Pounds 


Grain 
Bushels 


Stover 
Pounds 


1 
2 

3 

4 


None 

fAcidphos. 1601 u-x 

Mur. potash 100 ^^bitrary 
1 Nitrate soda 160 1^^^^*'*^ 
[ Acid. phos. 60 ] ratio 
j Mur. potash 30 [ in corn 
I Nitrate soda 160 J plant 
None 


22.22 
42.71 

34.95 
17.46 


1441 
2326 

1946 
1248 


22.08 
15.90 


949 
634 









The ratio between the elements in the two mixtures and 
that required by the plant is shown in the following state- 
ment : — 

1 Ohio Agr. Exp. Sta., Circ. No. 104 : 3. 1910. 



140 



CORN CROPS 





Nitrogen 
Pounds 


Phosphoric 

Acid 

Pounds 


Potash 
Pounds 


Arbitrary mixture .... 

Ratio 

Natural proportion .... 

Ratio 

Elements required for 40 
bushels corn 

Ratio 


24 

6 

24 

_6 

59 
6 


24 
_6 

8 

2^ 

21.2 

2 


50 
12 
15 

34.0 
3 



The arbitrary mixture had approximately three times 
the phosphoric acid and potash in proportion to nitrogen 
that the natural proportion showed. 

In this- case the arbitrary mixture gave the best results, 
as the crop was able to obtain nitrogen from the soil to 
balance the fertilizer applied. The point is well illustrated 
in a second experiment in which the fertilizer mixtures were 
compared. The fertilizer was applied to corn in a three- 
year rotation of clover, corn, and wheat. A part of the 
benefit of the fertilizer went to the wheat and clover. 
Results with all three crops are given on the following 
page. 

Plot 19 received a smaller application of fertilizer at 
less cost, yet it contained twice as much phosphorus, 
which seems to be the one element that this soil most 
required. 

The above table emphasizes that the corn grower should 
handle nitrogen, phosphorus, and potassium more or less 
independently, adjusting his fertilizer application to the 
needs of the soil. The ready mixed fertilizer will not 
usually be as profitable as the fertilizer mixed especially 
for the case concerned. 



MINERAL MATTER FOR CORN LAND 



141 



TABLE XXIX 

Showing Fertilizers applied in Certain Experiments at 
THE Ohio Agricultural Experiment Station in a Three- 
years Rotation of Clover, Corn, and Wheat ^ 





Fertilizer 
Pounds per Acre 


Pounds of Elements 
applied per Acre 


Cost 




Nitro- 
gen 


P2O5 


K2O 


Acre 


17 
18 

19 
20 


None 
[Nitrate soda 160] 

Acid phos. 80 . . . 
IMur. potash 80 J 

Ratio 

[Tankage 100] 

Acid phos. 80 ... 
IMur. potash 10 J 

None 

Approximate ratio in plant 

(See table.) 


24 

7 
7 

7 


12.8 

4 
23 

2.5 


40 

11 

5 

4 


$7.45 
$2.30 





Corn, Twelve 
Crops 


Average Annual Increase per Acre 


Value 


Plat 


Grain 
Bushels 


Stover 
Pounds 


Corn 
Grain 
Bushels 


Twelve 
Crops 
Stover 

Pounds 


Wheat 
Grain 
Bushels 


Twelve 
Crops 
Straw 

Pounds 


Hay 
Pounds 


Cost of 
Treat- 
ment 


OF In- 
crease 

PER 

Acre 


17 

18 
19 
20 


36.55 
43.12 
44.37 
34.09 


2303 

2587 
2456 
2025 


9.25 
10.50 


471 
348 


2.83 
4.07 


309 
510 


599 

718 


$7.45 
$2.30 


$9.37 
$11.36 



pp. 17-18. 



142 



CORN CROPS 



FERTILIZER MIXTURES FOR CORN 

100. To mix the fertilizer so as to suit the requirements 
of the particular soil and crop, is the ideal way. As a 
basis for use when the fertilizer requirements are not 
known, general experience indicates that a formula of 
about 3-8-5 will most often be satisfactory. The Maine 
Agricultural Experiment Station ^ suggests the following 
formula : — 

TABLE XXX 

Formulas for Fertilizers suggested by the Maine Agri- 
cultural Experiment Station 



Crop and Fertilizing Material 


Weight 

Used 
Pounds 


Nitro- 
gen 
Pounds 


Phos- 
phoric 
Acid 
Avail- 
able 
Pounds 


Potash 
Pounds 


Corn on sod land, or in conjunction 
with farm manure. 

Nitrate of soda 

Acid phosphate •. 

Muriate of potash 


100 
400 
150 


16 


52 


75 


Total 

Percentage composition . . . 

Nitrate of soda 

Screened tankage 

Acid phosphate 

Muriate of potash 


650 

100 
200 
300 
150 


16 

2.S 

16 
11 


52 
8.0 

15 
39 


75 
11.5 

75 


Total 

Percentage composition 

Nitrate of soda 

Cottonseed meal 

Acid phosphate 

Muriate of potash 


750 

100 
200 
400 
150 


27 
3.6 

16 
14 


54 

7.2 

52 


75 
10 

4 

75 


Total 

Percentage composition . . . 


850 


30 

3.5 


52 

6.1 


79 

9.3 



1 Maine Agr. Exp. Sta., Bui. 107, 1904. 



MINERAL MATTER FOR CORN LAND 



143 



Director Charles D. Woods, who prepared the above 
formulas, makes the following statement in connection 
therewith: ''Corn is a crop that uses a large amount of 
nitrogen. It is usually grown upon sod land or with farm 
manure, or both. Indeed, it is doubtful if, under ordinary 
conditions, it would prove a profitable crop to be grown 
on somewhat exhausted soil with commercial fertilizers 
alone. . . . The first formula contains only about one- 
sixth of the nitrogen needed to grow the crop. With a 
good sod and especially with a liberal dressing of farm 
manure, that will ])e all that is needed. The second and 
third formulas carry more nitrogen. ..." 

101. The New York (Geneva) Agricultural Experiment 
Station ^ suggests the following formulas for corn : — 

TABLE XXXI 





Pounds of Different Constituents 


FOR One Acre 


Formula 










Principal Source of 


Principal Source of 


Principal Source of 




Nitrogen 


Phosphoric Acid 


Potash 


1 


1 

60 to 10.0 lb. ni- ! 350 to 700 lb. 


60 to 120 lb. 




trate of soda 


bone meal 


muriate of 
potash 


2 


50 to 100 lb. 


250 to 500 lb. 


60 to 120 lb. 




sulphate of 


dissolved 


sulphate of 




ammonia 


bone 


potash 


3 


100 to 200 lb. 


300 to 600 lb. 


250 to 500 lb. 




dried blood 


dissolved 
rock 


kainit 


4 


3000 to 4000 lb. 




600 to 1200 lb. 




stable manure 




wood ashes 


Pounds per 


Nitrogen 10 to 


Available phos- 


Potash 30 to 60 


acre . . 


20 


phoric acid 
35 to 70 




Percentage 


2 


7 


6 



1 N. Y. (Geneva) Agr. Exp. Sta., Geneva, N.Y., 14th Rept. 



144 



CORN CROPS 



102. As soils are continuously cropped, progressive 
changes take place. A suggested method of adapting the 
fertilizer to conditions is given by C. E. Thorne of the 
Ohio Agricultural Experiment Station, as indicated by 
experience on rather poor glacial soil at that station : ^ — 

TABLE XXXII 
Fertilizers suggested for Different Conditions 





Percentage Composition 


Conditions 


Ammonia 


Phosphoric 
Acid 


Potash 


For crops immediatelj^ follow- 
ing clover 

For crops one or two years 
after clover 

For crops two or three years 
after clover 

For crops on exhausted soils . 


1 

3 

4 

6 


13 
12 

12 
12 


2 
3 

4 

6 



WHEN IT PAYS TO FERTILIZE FOR CORN 

103. The gross income per acre from cereal crops is low, 
and their extensive culture can be carried on only where 
the soil naturally furnishes most of the mineral elements 
without excessive cost. In the past, cereal culture has 
largely followed the opening up of new lands, while it has 
declined on old soils when extensive use of commercial 
fertilizers has become necessary. 

From the foregoing discussion it seems that the use of 
mineral fertilizers for corn can be applied at a profit only 
as a supplement to soils already well supplied with avail- 
able minerals. In many cases when a single mineral 

1 Ohio Agr. Exp. Sta., Eul. 141. 1903. 



MINERAL MATTER FOR CORN LAND 145 

element is lacking in an available from, this element may 
often be directly supplied at a profit ; but ordinarily, 
in order to obtain the highest availabihty from the min- 
erals, fertilizers must be used in connection with barnyard 
manures, and in a properly balanced crop rotation where 
most of the nitrogen is supplied by legumes and the soil is 
kept well supplied with decaying organic matter. 

A review of the experimental evidence regarding the 
use of commercial fertilizers for corn seems to justify the 
following principles. 

1. It seldom pays to use miner-al fertilizers alone on 
land in a low state of fertility or on land that would not 
produce more than 20 l)ushels of corn per acre under 
favorable conditions.^ 

2. Even on good land it seldom pays to apply mineral 
fertilizer alone directly to the corn crop.^ 

3. It seldom pays to use fertilizers where corn is grown 
continuously or where it is rotated with grain crops only. 
Under such conditions, according to the Ohio station, 
only 60 per cent of the fertilizer is recovered in the crop.^ 

4. Commercial fertilizer pays, as a rule, only when used 
in connection with a rotation where manure or a legume 
crop, or both, are plowed under."^ In this case it is usually 
best to apply the fertilizer to the sod land, or, when wheat 
is grown in the rotation, a part may be applied to the wheat. 
The above expecially applies to phosphates and potash. 
Sodium nitrate is a partial exception to the above general 
rule, as it is sometimes applied with profit to the growing 
corn. 

lU. S. Dept. Agr., Farmers' Bui 1U-' 10; Farmers' Bui. 4U ■' 12. 
1910. R. I. Agr. Exp. Sta., Bui. 113 : 113. 1906. 

2 Ind. Agr. Exp. Sta., Bui. 77 : 32. 1899. 

3 Ohio Agr. Exp. Sta., Bui. 110 : 68. 1899. 

4 U. S. Dept. Agr., Farmers' Bui. I44 : 10. 1901, 

L 



146 CORN CFOPS 

Special cases : There are exceptions to the above rules, 
a striking example of which are certain rich muck lands in 
Illinois, well supplied with all elements except potassium, 
where an application of potassium salts pays large returns.^ 

It is not to be inferred that fertihzers do not afford a 
stimulus and give increased production, for they do ; but 
the gross income from an acre of corn is not sufficiently 
increased to pay the cost of fertilizer, except in certain 
cases when used in connection with manure and legumes. 
This makes it apparent that profitable corn growing 
must be carried on as a part of a general farming scheme 
in which the soil fertility is principally maintained by the 
use of green manures or barnyard manure, which may be 
supplemented in a limited way with commercial fertilizer. 

NITROGEN 

104. A large or excessive supply of available nitrogen is 
not considered favorable for most of the cereals, as wheat, 
oats, or barley ; the effect being to produce an excessive 
gro^i^h of straw, and often a decreased yield of grain. 
Corn, however, is not so affected, and is most productive 
on heavily manured land or on newly drained alluvial or 
swamp lands where the available nitrogen is so abundant 
that wheat or oats would " run to straw " and produce 
little or no grain. In fact, a well-manured clover sod 
where available nitrogen is in greater excess than any 
other necessar}'' element is ideal corn land. 

A large suppl}^ of nitrogen has sometimes been found a 
disadvantage earl}^ in the season, as it may stimulate a 
groT\i:h of plant too large to be adequatel}^ maintained 
during the remainder of the season. For example, the 

3 Hopkins, C. G. Soil Fertility and Permanent Agriciilture, p. 471. 



MINERAL MATTER FOR CORN LAND 147 

" Williamson " ^ method of corn culture advocates the 
withholding of soluble nitrate fertilizer until the plants 
are six to eight weeks old, thus tending to retard stalk 
growth but to give the needed stimulus at the time when 
ears are forming. 

West of the Missouri River, where the soil is loose and 
nitrification begins early in the season, it often happens 
that on very fertile soil a vigorous spring growth is stimu- 
lated, and later, if the season proves unusually dry, the 
growth cannot be sustained ; and such fields suffer more 
than do fields in a less fertile condition. On the other 
hand, with abundant water supply those fields would have 
been more productive. 

LIME 

105. Lime is an essential element required by plants. 
It is not commonly applied as a fertilizer, as only about 
12 pounds of lime are required by a 50-bushel corn crop, 
and most soils are abundantly supplied in so far as having 
sufficient lime for plant growth is concerned. 

The most important use of hme is as a soil amendment, 
when it assists in several ways in making the soil more 
favorable for plant growth : — 

1. Acid in the soil is neutralized. 

2. Potash and phosphate in the soil are made more 
readily available. 

3. Organic matter decays more rapidly and the organic 
nitrogen and minerals become available to plants in less 
time. 

4. The soil is made a more favorable medium for bene- 
ficial bacteria forms. 

1 The WiUiamson Plan. S. C. Agr. Exp. Sta., Bui. 135. 1908. 



148 



CORN CROPS 



5. The mechanical condition of heavy clay soils is 
improved. 

According to Bulletin 64 of the Bureau of Soils, United 
States Department of Agriculture, one hundred sixty-eight 
experiments with lime for corn have been reported by 
experiment stations. The average increase reported is 
3.2 bushels per acre at a cost of $8.91 for the lime. For 
corn soils in general liming would not pay, but, on the 
other hand, certain experiments show large profits from 
the use of lime. 

The Tennessee station reports an increased yield, at less 
cost per bushel, than for any of a number of mineral fer- 
tilizers tried in comparison, as shown in the following 
table : — 

TABLE XXXIII 
Fertilizers with Hickory King Corn, 1901-1902 







Cost of 
Fertilizer 
per Acre 


Yield per 


Increase 


Cost per 


Fertilizer Used 


Amount 


Acre of 
Grain- 
Bushels 


Due to 
Fertilizer 
Bushels 


Bushel 

OF 

Increase 


No fertilizer . 






41.94 






Farmyard 












manure . 


8 tons 


$3.20 


48.71 


6.77 


$0.47 


Lime . . . 


25 












bushels 


1.50 


49.22 


7.28 


.10 




Nitrate of 


100 












soda . . 


pounds 












Acid phos- 


150 












phate . . 


pounds. 


4.00 


43.97 


2.03 


1.74 




Muriate of 


5 












potash 


pounds 











At the Ohio station ^ the addition of lime increased the 
yield of corn 10 bushels per acre, or about 30 per cent, both 

1 Ohio Agr. Exp. Sta., Bui. 159 : 173. 



MINERAL MATTER FOR CORK LAND 149 

on plats where lime was used alone and where it was used in 
connection with other fertilizers. In commenting on 
results with lime, Director Thorne says : — 

" Taking the results as a whole, it would seem that the 
lime has performed two distinct offices in this test : in the 
first place, it has increased the yield by an average of 
about 10 bushels per acre, or 30 per cent of the unfer- 
tilized yield. This it must have done in one or both of 
two ways ; either it has furnished a needed element of plant 
food to the growing crop, or else it has rendered the plant 
food already in the soil more available, either by direct 
chemical action of the lime itself on the soil stores of nitro- 
gen, phosphorus, and potassium, or by opening up the soil 
and giving the air, water, and frost a better opportunity to 
reach these stores and prepare them for plant nutrition. 

" The other office performed by the lime seems plainly 
to have been the setting up of conditions favorable to the 
growth in the soil of the micro-organisms by which the 
stores of organic nitrogen are gradually converted into 
available form through the process of nitrification. This 
is indicated by the fact that the giving of large quantities 
of available nitrogen in the fertilizers appears to have 
reduced the effect ascribable to lime, whereas this effect 
seems to have been augmented by fertilizers containing 
little or no nitrogen." 

It may be said in general that lime as a soil amendment is 
more likely to be beneficial on heavy clay soil, in humid 
regions, where aeration is poor and the products of organic 
decomposition are very likely to be toxic to plants. In 
regions of low rainfall or sandy soils, lime is not so likely 
to be required as a soil amendment. 

There are various chemical tests for determining the 
probable lime requirement of a soil, but the most reliable 



150 CORN CROPS 

test is to apply lime experimentally and note results for at 
least two years. 

References on fertilizers : — 
VooRHEES, E. B. (1898.) Fertilizers. 
Lyon and Fippin. (1909.) Soils, pp. 267-386. 
Bailey, L. H. (1911.) The Farm and Garden Rule Book, 

pp. 40-91. 
Hopkins, C. G. (1910.) Soil Fertility and Permanent Agri- 
culture. 
Ohio Agr. Exp. Sta., Bui. 141 ; Circ. 104. 
Maine Agr. Exp. Sta., Bui. 107. 
Vt. Agr. Exp. Sta., Bui. 116; Circ. 7. 

References on lime : — 
Agriculture Lime. Conn. (Hatch) Agr. Exp. Sta., Bui. 163. 
Lime and Liming. R. I. Agr. Exp. Sta., Bui. 46. 
Chemical Methods of Ascertaining Lime Requirements of Soils. 

R. I. Agr. Exp. Sta., Bui. 62. 
Liming Acid Soils. U. S. Dept. Agr., Farmers' Bui. 133. 
Liming the Soil. Ohio Agr. Exp. Sta., Bui. 159. 
Carriers of Lime. Ohio Agr. Exp. Sta., Circ. 123. 
The Rational Use of Lime. Mass. Agr. Exp. Sta., Bui. 137. 
Increasing the Yield of Corn. Tenn. Agr. Exp. Sta. BuL, 

Vol. XVII, No. 2, p. 46. 
The Use of Lime upon Pennsylvania Soils. Penn. Dept. of 

Agr., Bui. 61. 1900. 



CHAPTER XV 

REGULATING THE WATER SUPPLY 

A 50-BusHEL corn crop requires 7 to 10 inches of water 
for the use of the plant, besides that to be allowed for 
run-off, seepage, and evaporation. In Nebraska, with a 
29-inch rainfall, the division of this water between the 
four sources of losses is estimated as follows, when a 50- 
bushel crop is grown : — 

Water required by the plants 8 inches 

Water lost by run-off 3 inches 

Water lost by seepage 2 inches 

Balance lost by evaporation 16 inches 

Total .29 inches 

The proportion of total rainfall lost by the different 
means will vary with the region, but it is probable that 
in most cases evaporation is twice the amount required by 
the crop. 

106. Not all evaporation is undesirable. Whenever the 
soil reaches its water-holding capacity, as is often the case 
in early spring, then it must be dried by evaporation before 
cultivation can be practiced. Run-off is desirable after the 
soil reaches saturation, if the run-off takes place in such a 
way as not to cause erosion, since the taking up of this 
water by the soil would increase the loss by drainage, and 
excessive drainage means a slow leaching of the soil. 
The amount of run-off necessary in order to care for ex- 
cessive rainfall, or of evaporation necessary in order to 
dry out the soil, will vary witli the rainfall. In fact, all 
the water above that actually used by the crop is exces- 

151 



152 



CORN CROPS 



sive and must be disposed of in some way, as by drainage, 
run-off, or evaporation. 

Even though the crop requires a relatively small pro- 
portion of the total rainfall, the crop often suffers due to 
the fact that this small proportion is required during a com- 
paratively short period and in excess of the water-storing 
capacity of the soil. 

Lyon and Fippin^ give the following statement regp^rding 
the water-holding capacity of some soils : — 
TABLE XXXIV 





Water Capacity 


Amount of Available Water 




Minimum 
Per Cent 


Maximum 
Per Cent 


Per Cent 


Cu. in. per 
Cu. ft. 


Inches per 
Acre, 4 ft. 


Light sandy 

loam . . 

Silt loam ." . 

Clay . . . 


3 
15 
23 


8 
25 
40 2 


5 
10 
17 


122 

218 
274 


3.4 

6.0 

7.6 



Studies at the Nebraska station indicate the water 
requirements of a 50-bushel corn crop for the different 
months to be about as follows : — 

TABLE XXXV 



Inches 



January 1 to June 1 

June 

July 

August 

September .... 
October 1 to January 1 
Total .... 



.00 

.50 

3.60 

3.30 

.60 

00 

8.00 



1 Lyon and Fippin. Soils, p. 158. 



2 Assumed. 



REGULATING THE WATER SUPPLY 153 

Most of this water is required during a period of five oi 
six weeks, ranging from about July 10 to the end of August. 
On p. 65 it was pointed out that evaporation from the soil 
and loss from run-off probably equals or nearly equals 
the requirements of the plants in making a 50-bushel crop, 
or the total requirement by the crop, and evaporation 
from the soil, etc., for July and August probably amounts 
to 12 inches. This is twice the storage capacity of the 
soil and perhaps three times the amount usually available 
early in July. After the water stored in the soil is ex- 
hausted, if rains are delayed, the crop suffers, being 
greatly reduced, and this often happens even when abun- 
dant rains come later. The seasonal requirements of corn 
are illustrated by Fig. 24. 

107. Three ways are open for regulating the water 
supply : (a) increasing the water-holding capacity of the 
soil ; (6) conservation by preventing evaporation ; (c) 
decreasing run-off during the growing season. 

Since the water-storage capacity of soil is closely related 
to its physical composition, httle can be done to improve 
this condition in a practical way. The addition of vege- 
table matter helps onl}^ to a limited extent. 

A certain amount of evaporation can be prevented by 
cultivation, but how much has never been satisfactorily 
determined under field conditions. It is probable, how- 
ever, that loss by evaporation of water that has reached a 
depth of 12 inches in the soil is very small, and that culti- 
vation serves principally to prevent evaporation of mois- 
ture from rains that penetrate no deeper than 6 to 10 
inches. Experimental results under field conditions to 
show the effect of cultivation give extraordinary variation. 
For example, at the Illinois Agricultural Experiment 
Station, plats of corn that were not cultivated but merely 



154 CORN CROPS 

had the weeds shaved off gave as good results as an aver- 
age of five years as when carefully cultivated, and similar 
results have been secured at other stations. (See p. 206.) 
On other occasions cultivation has apparently conserved 
sufficient moisture to improve the jqeld. The underlying 
principles have not been clearly worked out. 

It seems apparent that a well-cultivated surface, with 
a good store of organic matter, will take up a moderate 
rain more readily and store a large percentage of it deep 
enough to protect from surface evaporation than will a 
hard and uncultivated surface ; also, that when this mois- 
ture is stored continuigd cultivation will decrease the rate 
of loss from the upper 10 inches of surface. 

EKOSION 

108. Effect of erosion. — Erosion affects the agricul- 
tural value of land in two ways : first, by producing 
guUies and large ditches, thus increasing the expense of 
crop cultivation and resulting in the actual loss of some 
land; second, by reducing available fertility, through 
removing the surface. 

In the latter case, the damage to productivity depends 
on the soil. In heavy clay soils, much of the available 
fertility seems to be in the surface 6 inches. On such 
soil productivity is often reduced for many years by turn- 
ing up "too much subsoil at one time with the plow. On 
the other hand, as pointed out by King,^ in many regions, 
especially of low rainfall, the subsoil, even to several 
feet deep, is as productive as the surface soil In a case of 
such surface, erosion would work little or no damage. 
However, in most of the regions where erosion, is severe, 

1 King, F. H. The Soil, p. 29. 



REGULATING THE WATER SUPPLY 155 

as in eastern United States, the soil is heavy in texture, 
the exposed subsoil not productive, and the loss of surface 
soil causes serious damage. When manure, mineral 
fertilizer, or lime is used, much of this added material 
remains in the plowed surface and erosion causes a direct 
loss of this material. 

109. Causes of erosion. — In the corn-growing area of 
the United States — that is, from the Atlantic Coast 
westward to the 100th meridian — erosion is related to 
the amount of run-off water and to the condition of the 
soil at the time the run-off takes place. In the principal 
corn-growing States, north and west of the Ohio River, 
erosion is not serious. The land is generally level and 
rainfall not excessive. Also, during a part of the year the 
ground is frozen, and in June, July, and August, when 
about 40 per cent of the rainfall occurs, the land is in crop. 

From Ohio eastward, however, the rainfall is heavier and 
cultivated land is more rolling, thus increasing the total 
run-off and erosion. From the western edge of the Corn 
Belt to the Atlantic Coast, erosion gradually increases. 
In Kansas and Nebraska, with level farming land, the 
rainfall is 25 to 30 inches and the total run-off about 3 
inches. In the North Atlantic States rainfall is heavier, 
land more rolling, and the run-off is estimated at 40 to 50 
per cent of the rainfall, which often amounts to a run-off of 
26 inches or more. In the Southern States the most 
serious erosion takes place during the winter months. 
The soil is not frozen, is without a crop, and heavy rainfall 
occurs during this period. 

The relation of cropping systems to erosion may be 
grouped as follows : — 

(a) Land in grass erodes least. 

(6), Land in stubble or small grain erodes more than (a). 



156 COTIN CROPS 

(c) Land in cultivated crops erodes more than (6) . 

(d) Cultivated land not in crops erodes most. 

110. Preventing erosion. — Since the character of the 
crop and the grade of the land both have a marked effect 
on the degree of erosion, they are the two principal means 
of preventing the same. 

Land subject to severe erosion should be kept principally 
in grass crops and small grain, and never left longer than 
necessary without a growing crop. If a good supply of 
vegetable matter is maintained and deep plowing practiced, 
cultivated crops can often be grown on rolling land with 
little loss by erosion where otherwise the loss would be 
severe. It is often noted that new land just brought under 
cultivation does not erode, but as the humus supply 
decreases, erosion increases. Also, the plowing under of a 
heavy coat of barnyard manure or a green manure crop 
will often stop erosion where it is otherwise serious. Deep 
plowing enables the soil to take up water readily and give 
it up slowly, and in many cases deep plowing alone has 
been found to entirety prevent erosion. 

The second method of preventing erosion is by decreas- 
ing the grade. This is usually done by terracing, causing 
the water to follow the contour of the hills at a low grade. 
The same effect is secured in some degree by plowing and 
planting with the contour of the hills. 

To summarize : Erosion is better controlled when the 
land is in grass or small grain than when in a hoed crop. 
Sufficient organic matter and deep plowing decrease erosion. 
The land should not be left bare. The grade can often be 
decreased by terracing. 

The most serious loss due to erosion is the constant re- 
moval of the accumulated organic matter of the surface 
soil. 



REGULATING THE WATER SUPPLY 157 

DRAINAGE 

111. Corn requires a thoroughly drained soil, both be- 
cause it flourishes in a '' warm " soil, and because it re- 
quires large amounts of available nitrates when making its 
rapid summer growth. On poorly drained land, even 
when such land is rich bottom soil, the corn plant will 
often have a yellow color indicating a need of nitrogen. 





,^^ 



v\ATER 
FURROW 



8 FT. 



Fig. 40. Plan of ridging land for surface drainage. Two rows on each 

ridge. 

The water-logged soils interfere with bacterial activity 
and the normal nitrifying processes are prevented. Sur- 
face drainage for corn on very flat lands is often provided 
by plowing in narrow beds, 8 feet wide, and planting two 
rows of corn 4 feet apart on each bed. 

Underdrainage is so thoroughly discussed in several 
soil texts that it is not necessary to take up the subject 
here. 



SECTION IV 
CULTURAL METHODS 



CHAPTER XVI 
PREPARATION AND PLANTING 

So far in this book it has been the plan to discuss the 
fundamentals relating to the nature of the corn plant, its 
requirements, the conditions that must be met in the grow- 
ing of corn, and methods of modifying the plant to im- 
prove yield or quality. 

Having considered the above problems, the next step 
is to consider cultural methods. The basic principle in 
cultural methods is largely protection of the crop against 
unfavorable conditions that may arise, as draught, weeds, 
insect or parasitic enemies. The cultural method to be 
adopted in a particular case is the one that most effec- 
tually insures the crop, and at the least cost. 

Cultural methods must vary with the local situation." 
In regions of high priced labor and level lands, extensive 
systems have been developed. In regions of low priced 
labor and small fields more intensive methods are prac- 
ticed. The other crops to be grown, the character of the 
climate, the use of the crop, and many other factors all 
help to determine the most practical method to be 
adopted. As with other farm problems, the farmer him- 
self must largely determine the cultural method to be 
used on his own farm. 

THE OLD CORN STALKS 

112. In the corn-belt and the Southern States, corn stalks 
are not harvested, but stand in the fields, to be plowed 
M 161 



162 



COBN CROPS 



under the following spring. In the early days of corn 
culture in the middle west, the corn stalks were usually 
burned. The common custom was to break down the 
frozen stalks with a log or an iron rail and later when the 
ground had thawed, they were raked with horse rakes 
into long windrows, and burned. For a week or two in 
each spring, the sky would be lit up every night by the 




Fig. 41. — Two-row stalk-cutter. 



great burning fields of corn stalks. This so rapidly re- 
duced the organic matter in the soil that it soon became 
necessary to plow the stalks under, in order to obtain 
humus, as is now the general custom. 

To prepare for plowing , the stalks are broken with a rail, 
as before, and then usually gone over with a sharp disk, 
to cut them up. The stalk-cutter is also in general use. 
This implement has heavy revolving cyHnders set with 
knives that cut the stalks in twelve inch lengths. Where 
the stalks are heavy it is more satisfactory than the disk 
harrow, although the stalk-cutter is often followed also 
with a disk-harrow. 



PREPARATION AND PLANTING 163 



TIME OF PLOWING 

113. When, land is fall-plowed it is exposed more com- 
pletely to the action of frost, thus giving a finer state of 
pulverization. This is often an advantage with heavy 
soils, but in light soils it may actually be a disadvantage. 
Also, when a cover crop is to be turned under, there is 
more time for decomposition when turned under in the fall. 

When the soil is infested with the larvae of injurious 
insects, fall plowing just as freezing weather begins will 
often destroy many of these. For early planted crops 
there is not always enough time for proper preparation of 
all the land in the spring, and it is good farm management 
to do part of the plowing in the fall. 

Early spring plowing for corn, compared with late 
spring plowing, has not been the subject of extensive 
investigation. An experiment carried for a single season 
by Quiroga,'^ at the Ohio State University, showed an 
increase of about 7 per cent in the crop with early 
spring plowing overlate, and a marked increase in avail- 
able nitrogen was found in the early plowed land through- 
out the season. 

DEPTH OF PLOWING 

114. From experiment stations some twenty-six tests 
have been reported on deep and shallow plowing for corn. 
These results cannot be regarded as very significant as a 
guide in specific cases, since the results were obtained 
under a great variety of conditions. They may be sum- 
marized as follows : — 

Favorable to deep plowing 14 

Favorable to shallow plowing 6 

Indifferent results 6 

1 QuiROGA. Ohio State Univ. Bui., Series 8, No. 28. 



164 CORN CROPS 

There are no experiments to show the ultimate effect 
of following a system of continuous shallow plowing or 
continuous deep plowing, but practical experience has 
shown that land should be occasionally plowed deep 
(8 inches) to keep the surface in best mechanical 
conditions. Heavy soil requires deep plowing more 
often than do light soils. Probably a very heavy soil 




Fig. 42. — Plowing under alfalfa sod in preparation for corn. 

should be plowed deep once each year, while certain light 
soils, especially where rainfall is low, do very well with 
deep plowing every two or three years. 

Hunt ^ summarizes certain experiments with deep and 
shallow plowing as shown on the following page. 

It has been demonstrated many times, that if the soil 
has been kept in a good productive condition, that the 
preparation immediately before planting or even the 
system of cultivation after planting is not likely to have 
an important effect on the yield of the current crop. The 
crop secured does not depend so much on treatment of 

,1 Hunt, Thos. F. Cereals in America, p. 220. 



PREPARATION AND PLANTING 



165 



soil for the present crop, so much as the kind of treatment 
it has had for the last ten or twenty years. The kind of 
treatment to be recommended must consider more the 
future welfare of the land, than present benefits to be 
derived. 

TABLE XXXVI 

Yield of Corn in Bushels 



Station 



Illinois ...... 

Illinois 

Indiana (average 3 

years) 

Pennsylvania (average 

3 years) 

New Hampshire ^ . . 
Alabama ..... 

Minnesota .... 

Ohio 3 ...... 

Nebraska 



Depth of Plowing 
Inches 



52.9 
54.0 



69.4 



39.5 

47.0 
14.2 
24.1 
65.8 
43.1 
38.5 



69.3 
57.5 

40.5 

62.0 
26.2 

64.4 



71.7 



42.3 

57.5 
29.4 

59.52 

42.9 

31.0 



10 



56.0 
41.8 

58.5 
28.2 
24.2 



13 



42.0 



1 Tons of green silage. Depths were 3, 5, 7, and 9 inches. 

2 Also subsoiled 6 inches deeper. ^ Depths 3 and 7 inches. 

So far as tillage is concerned, as a factor in maintaining 
crop production, the following principles may be set forth : 

That all land should occasionally be plowed 8 to 10 
inches deep. On heavy land about once a year, but on 
lighter soil, and in rather dry regions, once in two or three 
years being sufficient. 

The plowing should be done when the land is in proper 
condition to pulverize. 

Quite thorough treatment with pulverizing tools, as 



166 CORN CROPS 

harrows, rollers, and cultivators, is essential to keeping the 
soil in good mechanical condition. 

SUBSOILING 

115. The subsoiler is a tool for loosening the subsoil 
without bringing it to the surface. While tools for this 
purpose have been in use for many years and have been 
generally tried out in all the principal agricultural regions, 
yet subsoiling is nowhere in general practice. General 
experience has confirmed results obtained at the Nebraska 
station, where, in a cooperative test with fifty-nine farmers 
for three years, beneficial results were obtained on soils 
having a heavy or impervious subsoil, but on loam sub- 
soils the results were indifferent or injurious. 

preparation" OF PLOWED LAND 

116. The amount of fitting that must be given to land 
after plowing depends on the soil and the seasonal condi- 
tions. A good loam soil, plowed when in just the proper 
condition, may need very little fitting with the simplest 
tools, as harrow and float, in order to bring it to a proper 
mechanical condition. On the other hand, the same soil if 
plowed when too wet, or if when wet it had been tramped 
by stock in pasturing, would require more labor and a 
greater variety of tools for proper fitting. This emphasizes 
the importance of plowing only when the soil is thoroughly 
pulverized by the plow. Also, further pulverizing of the 
soil, with harrow or cultivator, is most easily accomplished 
mthin twenty-four hours or less after ploTvdng, and one 
harrowing at this time may accomplish several times as 
much as a few days later, when the clods have dried. 

There are certain heavy clay soils that always require a 



PREPARATION AND PLANTING 167 

great deal of fitting for good results. The best tool for 
pulverizing to a depth of several inches is the disk-harrow 
Where the land is stony or hard, a cutaway is more effec- 
tive. On very stony or rough land, a spring-tooth is more 
practicable than the disk, or the ordinary cultivator can 
also be used to good advantage. For surface finishing, the 
spike-tooth harrow and weeder are used for pulverizing 
and the board drag and roller for further reduction.^ 

Repacking the soil after deep plowing is an important 
function of all tillage in preparing the seed-bed. When the 




Fig. 43. — A inodcrn disk-han-ow. A tool that pulverizes the surface and 
packs the subsurface at one operation. 

plowing is done long in advance, so that heavy rains may 
come, little attention need be given to repacking. A fairly 
compact seed-bed is desirable at planting time, though not 
so important with corn as with wheat. 

A good method of repacking a loose seed-bed is to use 
either a subsurface packer, or quite as well a disk-harrow, 
set straight (no angle to disks) and loaded with sufficient 
weight to cut nearly through the furrow slice. These 
tools will pack the bottom of the furrow slice. To pack 



168 CORN CROPS 

the surface, a roller or a smoothing harrow, or both, may 
be used. 

Clearing of weeds is important in preparation. One 
principal advantage of early plowing is that more weeds 
may be germinated and destroyed before planting. While 
weeds are germinating rapidly, it is often an advantage to 
delay planting until the land can be entirely cleared, as it is 
much easier to destroy weeds before planting than after- 
ward. 

To sum up, it is important to plow the land when in 
just the right tilth for plowing, to pulverize thoroughly 
to repack when the seed-bed is loose, and to destroy weeds 
before planting. 

PLANTING THE SEED 
METHODS 

117. (1) The seed may be " surface" planted, the land 
being prepared level and the seed planted in rows 1 to 3 




Fig. 44. — Combined lister plow and drill. 

inches below the surface. (2) The planter may have a 
furrow opener, usually a pair of disks which open up a 
shallow furrow, the seed being planted in the bottom of 
this. (3) A lister may be used, which is essentially a 
double-moldboard plow throwing a furrow slice each way. 
The land is furrowed as deep as possible with the lister, 
the corn being planted in the bottom. 



PREPARATION AND PLANTING 



169 



Surface planting is the method in common use on all 
heavy lands or in regions where rainfall is plentiful, being 
the common method in all the States east of the Missouri 
River. The " furrow opener," or disk planter, is also 





♦ 




A^y'l 


t^'-£ 


^•^ 


?:<Y4^ 


i -1a^ 


M ^^■nL^s 1 


Bfc^— ■!l.li_. *' 


m 


^B 


IH^V 


IkI^^^ 


p^^^^s 


K^-.«iH 


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> 





Fig. 45. — A combined lister and drill. The land is not plowed in prep- 
aration for listing. 

popular with many farmers, especially when it is desirable 
to drill, as in the growing of silage or fodder corn. 

The lister came into vogue about twenty-five years ago, 
but it is used extensively only where the soils are rather 
light in texture (loam or sandy loam) and in regions of 
rather low rainfall. In central Nebraska, Kansas, and 
Oklahoma, one-half or more of the corn is listed. List- 



PREPARATION AND PLANTING 171 

ing is not practicable on land subject to washing, as 
the planting is likely to be destroyed by heavy rains. 
Also, in cold or wet soils the seed is likely to rot in the 
lister furrows, or growth of the young plants to be much 
retarded. Where listing is practicable, namely, in dry, 
warm soils, it is a very cheap method of producing corn, 
as the ground is not plowed before planting, though it is 
usually disked. Cultivation is simple and easy. 

SOWING CORN FOR FORAGE 

118. For coarse forage or soihng, corn is frequently sown 
broadcast or drilled thick with a grain drill. One to two 
bushels of seed are sown per acre. Usually a rather small 
early .variety is used, rather than a tall or late variety. 




Fig. 47. — Corn sown broadcast for forage. In above ease was sown after 
wheat harvest. 



172 



CORN CROPS 



Early sweet com is well adapted for this purpose and is 
often sown in July after a small-grain crop has been har- 
vested. 



CHECKING AND DRILLING 



119. When corn is to be surface planted it is usually 
" checked/' that is, planted in hills and r'owed both ways, 
thus permitting of cross cultivation. When corn is drilled 
on the surface, it is often difficult to keep weeds out of the 




Fig. 48. • 



A two-row corn planter. Will drop in hills, rowing both ways, 
or in drills. Commonly called a check-rower. 



row, as little soil can be thrown around the plants in 
cultivating. This difficulty is overcome in a large measure 
by using the furrow opener and placing the corn in a 
shallow furrow. 

TIME OF PLANTING 

120. Many experiments have been made on the time 
of planting, but the principal conclusion may be stated as 



PREPARATION AND PLANTING 



173 



finding an average range of about six weeks for corn 
planting. The very earliest and the very latest plantings 
are usually not so successful as those about midseason. 
For example, the Illinois station in 1890 made plantings 
from April 28 to June 9. The average yield of the corn 





Fig. 49. — Special attachments for corn planter shoes. 

planted in May was 73 bushels per acre, while the average 
yield of the three remaining plantings, one in April and 
two in June, was 63 bushels per .acre. 

Many experiments at other stations bear out the state- 
ment that there is a period of about three weeks for corn 
planting with equal chance of success, though there are 
occasional seasons when the very early or very late plant- 
ings are best. The optimum season is shorter in the North 
and longer in the South. 

TABLE XXXVII 

Time of planting Corn in Certain Regions * 



Region 


Beginning 


General 


Ending 


Planting 

Period 

Days 


Gulf States 

Central States (Virginia 

to Kansas) .... 
Northern States (New 

York to Minnesota) . 


March 15 
April 15 
May 10 


April 5 
May 1 
May 2D 


May 10 
May 25 
June 1 


55 
40 
20 



U. S. Dept. Agr. Yearbook, 1910, p. 491. 



174 



CORN CROPS 



The above table shows that the planting season begins 
about two months earlier in the Gulf States, as compared 
with the Northern States, but the total length of the plant- 
ing season is about three times as long. 

The average of the beginning of corn planting is also 
shown by the accompanying chart : — 



MAV'« 




rss/s 



Fig. 50. — Chart showing average date of planting corn in the United 

States. 



The percentage of moisture in the crop at harvest time 
usually increases with the lateness of planting, after a 
certain date, as illustrated by the following data from the 
Illinois station : ^ — 

1 111. Agr. Exp. Sta., Bui. 20. . 1892. 



PREPARATION AND PLANTING 



175 



TABLE XXXVIII 
Data taken at Husking Time 





Pounds to 


Percentage 


Bushels of 


Bushels of 


Date op 


MAKE One 


OF Moisture 


Air-dry 


Planting 


Bushel in 


IN Shelled 


per Acre 


Corn per 




Dry Corn 


Corn 


Acre 


April 25 . . 


69.9 


14.0 


52.6 


50.8 


May 2 




70.8 


14.6 


52.6 


50.4 


May 9 




70.9 


14.8 


50.7 


48.5 


May 16 




74.4 


17.0 


53.3 


49.7 


May 23 




80.0 


19.3 


57.9 


34.1 


May 30 




96.8 


24.0 


40.0 


37.5 


June 8 




97.9 


23.9 


43.9 


37.5 


June 13 




127.8 


31.5 


25.2 


19.4 



DEPTH OF PLANTING 

121. Corn is usually planted 1 to 4 inches deep. Re- 
sults from several experiment stations are summarized as 

follows : — 

TABLE XXXIX 

Planting Corn at Different Depths 



Depth of 

Planting 

Inches 


Yield per Acre in Bushels 


Ohioi 
Average 
6 Years 


Indiana 2 
Average 
6 Years 


Illinois 3 
Average 
5 Years 


1 

2 
3 

4 
5 
6 


56.6 
51.2 
46.8 


38.6 
39.2 

37.8 
28.8 


78.0 

72.0 
65.0 
69.0 
61.0 
60.0 



1 Ohio Agr. Exp. Sta., Bui. V. 3, No. 3, Nov. 3, 1890: 87. 

2 Ind. Agr. Exp. Sta., Bui. 64: 5. 1897. 
» 111. Agr. Exp. Sta., Bui. 31 : 353. 



176 



COBN CROPS 



In no case has the average yield been increased by plant- 
ing more than 2 inches deep. In heavy soils, such as of 
the Ohio station, shallow planting was decidedly better, 
while in loose loam soil, at the Illinois station, the depth of 
planting did not vary results so much. Also, when the 
soil is warm and dry the corn should be planted deeper 
than when the soil is cold. In two years out of seven at 
the Ohio station, when the soil was drier than common, the 
3-inch plantings gave the best results. 

Some persons have thought that deep planting would 
establish the roots deeper in the soil. It has been found, 
however, that the roots spread out at about the same depth, 
no matter what the depth of planting. Ordinarily the 
roots spread out about 1 inch below the surface. 

It would seem, then, there is no object in planting corn 
deeper than is necessary to insure plenty of moisture for 
good germination. 

RATE OF PLANTING 

122. The customary rate of planting varies with soils 
and climate. In the South the corn rows are often 5 feet 
apart and the hills 4 feet apart, with two stalks to a hill. 
The rate of planting increases toward the North. Cus- 
tomary rates are as follows : — 

TABLE XL 



Region 



Gulf States 

Middle States (Virginia to 

Kansas) 

Northern States (New York 

to Minnesota) 



Distance Apart 
OF Hills 



4' by 5' 
3'8" by 3'8" 
3'6" by 3'6" 



Plants 
PER Hill 



2 

2-3 

3-4 



Plants 
PER Acre 



4,000 

9,000 

12,000 



PREPAEATION AND PLANTING 



177 



The rate of planting is partly regulated by the size of 
plant. Plants in the GuK States are about twice as large 
as in the Northern States, due in part to climate and also 
to the longer growing season. 

It has been shown, however, that for a given place the 
rate of seeding within wide limits does not have a marked 
effect on yield. An experiment regarding this point was 
conducted by the Illinois Agricultural Experiment Station.^ 




Fig. 51. — A Southern method of planting on poor soils. Rows wide 
apart, and a crop of peanuts between. For soil improvement cowpeas 
are sometimes grown between. 



For three years corn was planted at rates varying from 
5,940 to 47,520 kernels per acre. The maximum yield 
was obtained with 11,573 kernels per acre, though almost 
as good yields resulted when 15,840 or 23,760 kernels were 



1 111. Agr. Exp. Sta., Bui. 13 : 410. 



178 



CORN CROPS 



planted. The average yields were 81, 77, and 76 bushels 
per acre, respectively. 

At the Nebraska station, corn was planted in hills 3 
feet 8 inches apart each way, the stand varying from one 
to five plants per hill. 

TABLE XLI 

Average Results from planting Corn at Various Rates 
FOR Six Years (1903-1908), Nebraska Station ^ 



Plants 
per Hill 


Yield 
PER Acre 
Bushels 


Average 
Weight 
OF Ear 
Ounces 


Number 

OF Ears 

PER 100 

Plants 


NUNfBER OF 

Tillers per 
100 Plants 


Two- 
Eared 

P*LANTS 
PER 100 


Barren 
Plants 
PER 100 


1 

2 
3 
4 
5 


48.3 
67.7 
75.5 
76.7 
76.3 


10.5 

10.6 

9.4 

8.2 
7.4 


161 

115 

95 

82 

77 


138 

60 

25 

10 

3 


13.32 

4.9 

2.4 

.8 

1.1 


3.0 
4.8 
6.9 
8.3 
10.8 



1 Nebr. Agr. Exp. Sta., Bui. 112 : 30. 

2 Four years omly. 



1909. 



There was practically no difference in yield when three, 
four, or five plants were grown to the hill. 



ADJUSTMENT OF CORN PLANTS 

123. As the number of plants increased, the size of ear 
and the number of ears decreased, while the number of 
barren plants increased. One stalk per hill produced 64 
per cent and two stalks per hill 90 per cent as much grain 
as did three stalks per hill, due principally to the increased 
size of ear and number of tillers producing ears and to the 
decrease in number of barren plants. It is evident that 
the corn plant is capable of a wide range of adjustment 



PREPARATION AND PLANTING 



179 



ECONOMIC VALUE OF TILLERS 

124. The question often arises as to whether tillers 
should be pulled when they appear in abundance. Data 
were taken at the Nebraska station for five years, and in 
every case the yield was decreased by removing tillers. 
For three years the corn was planted at different rates, the 
data being summarized as follows : — 

TABLE XLII 

Effect on Yield of Grain of removing Tillers from Corn 
Three-Year Average (1906-1908) 



NtTMBER 


Average Yield in Bushels 
PER Acre 


Average Yield of Stover in 
Pounds per Acre 


OF 

Plants 

PER 

Hill 


Tillers 
on 


Tillers 
Removed 


Difference 
in Favor 
of Tillers 


Tillers 
on 


Tillers 
Removed 


Increase 
Due to 
Tillers 


Per- 
centage 

Decrease 
Due to 

Removing 
Tillers 


1 
2 
3 
4 
5 


45.9 
66.1 
69.6 
73.2 
76.7 


31.8 
56.4 
64.4 
71.4 
72.6 


14.1 

9.7 
5.2 
1.8 
4.1 


5,061 
5,127 
5,115 
5,801 
6,043 


2,208 
4,200 
4,687 
5,602 

5,987 


2,853 
927 

428 

199 

56 


56.3 

18.1 

8.3 

3.4 

.9 



Tillers appear to develop in response to the needs of the 
crop, in an attempt to bring the stand up to normal. 
When the stand is maximum, few tillers develop. The 
occasions are certainly very rare when it would pay to 
remove tillers. 



OTHER FACTORS AFFECTING PRODUCTION OF TILLERS 

125. On some soils tillers do not develop even when the 
planting is thin. When early growth is slow or retarded, 



180 



CORN CROPS 



as on heavy or cold clay soils, there is not sufficient stimu- 
lus early in the life of the plant to start the tillers. 

RATE OF PLANTING ON DIFFERENT SOILS 

126. On good soils it is generally recognized that plant- 
ing should be thicker than on poor soils. This is shown by 
data obtained by the Illinois station.^ In a series of tests 
on different soils, corn was planted in hills at various dis- 
tances apart and two or three stalks per hill. Grouping 
the data so as to include all fields yielding more than 50 
bushels per acre in one class, and all yielding less than 50 
bushels in the other class, the following results are obtained : 

TABLE XLIII 

Rate of Planting and Yield on Soils producing More or 
Less than 50 Bushels per Acre 





More than 50 
Bushels per Acre 


Less than 50 
Bushels per Acre 


Region 


Two 
Kernels 
per Hill 


Three 
Kernels 
per Hill 


Two 
Kernels 
per Hill 


Three 
Kernels 
per Hill 


Northern Illinois . . . 
Central Illinois . . . 


57.9 
59.8 


68.5 

62.8 


41.4 
43.2 


42.4 
40.9 


Average .... 


58.8 


65.6 


42.3 


41.6 



On praductive soil the yield was increased by the thicker 
planting; but on the poorer soil two kernels per hill 
evidently furnished the maximum stand, as no further 
increase was secured by three kernels per hill. Data 
from the Indiana station show that in dry seasons the 

1 lU. Agr. Exp. Sta., Bui. 126: 366-377. 1908. 



PBEPABATION AND PLANTING 



181 



thin plantings give the best results, while in favorable 
seasons the reverse is true : ^ — 



TABLE XLIV 

Effect of Season on Yield and Percentage of Grain 



Stalks 
Inches 


Seasonable, 
1888-1891 


Ears 
Per- 
centage 


Dry, 

1893-1894 


Ears 
Per- 


Apart 










centage 




Bushels 
Corn 


Pounds 
Stalks 




Bushels 
Corn 


Pounds 

Stalks 




191 


49.76 


3,617 


49.1 


22.07 


3,092 


33.3 


16 


54.05 


4,065 


48.2 


21.27 


3,143 


32.2 


14 


57.79 


4,158 


49.3 


19.39 


3,762 


26.5 


15 


57.81 


4,201 


49.6 


14.28 


5,204 


16.1 


11 


59.14 


4,960 


45.5 


13.80 


4,360 


18.1 



This also indicates that in semiarid regions, as central 
Nebraska or Kansas, the regular practice should be rather 
thin planting. 

METHOD OF DISTRIBUTION OF PLANTS 

127. At the Illinois station, hill planting was compared 
with drill planting at various rates per acre. For example, 
four plants would be planted in hills every 48 inches, in 
comparison with two plants every 24 inches or 1 plant 
every 12 inches. The conclusion was that it made no 
difference in what manner the seed was distributed, so 
that approximately the same number of plants per acre 
were grown in each casCo 

At the Nebraska station, a uniform distribution of 
three grains per hill was compared with distributing the 

1 Ind. Agr. Exp. Sta., Bui. 64 : 4. 



182 



CORN CROPS 



seed in different amounts per hill but planting the same 
number per acre. The uniform distribution had a slight 
advantage, but not enough to indicate that the ordinary 
variation in dropping in corn planters would materially 
affect the yield. ^ 

WIDTH OF ROWS 

128. Width of rows is an important consideration, 
since the amount of labor required in planting and cul- 
tivating an acre is directly related therewith. 

TABLE XLV 



Distance 

Apart op 

Rows 

Feet 


Rods of 

Travel in 

Cultivating 

One Acre 


Percentage Increase in Labor 


4.0 
3.5 

3.0 


650 
754 

880 


16 per cent increase over 4 feet 
17 per cent increase over 3.5 feet 
35 per cent increase over 4 feet 



Numerous experiments have not shown a practical 
advantage in having rows closer than 36 inches in the 
northern limit of corn-growing States, 42 inches in the 
central corn States, and 48 inches in the Southern States, 
when the standard type of corn for the region is grown 
primarily for grain. A small early variety may be 
planted closer. 

When the corn is grown primarily for silage or fodder, 
somewhat closer planting will give a greater yield of 
forage. 

1 Nebr. Agr. Exp. Sta., Bui. 112 : 35. 



PREPARATION AND PLANTING 



183 



YIELD OP FORAGE 

129. When yield of forage is considered, numerous 

experiments have shown that the yield of forage increases 

with the rate of planting up to a point about twice that 

required for maximum yield of grain. The following 

data illustrate : — 

TABLE XLVI 

Yield op Grain and Stover when Corn was planted at 
Different Rates. Three-year Average. Rows 3 Feet 
8 Inches Apart. Illinois Station ^ 



Rate op Planting 
Kernels per Acre 


Bushels of 

Shelled Corn 

PER Acre 


Tons of Stover 
PER Acre 


Ratio of 

Shelled Corn 

to Stover 


5,940 
9,504 
11,880 
15,840 
23,760 
47,520 


55 

72 
81 
77 
76 
59 


2.5 
2.9 
3.0 
3.1 
3.7 
4.8 


100 : 162 
100 : 140 
100 : 130 
100 : 140 
100 : 174 
100 : 290 



lU. Agr. Exp. Sta., Bui. 13 : 410. 



EFFECT ON COMPOSITION 

130. The principal effect on composition when the rate 
of planting is increased is the change in ratio between 
percentage of ear and stalk. By referring to Table XLVI, 
last column, it will be seen that the proportion of stalk to 
ear increases as the rate of planting increases, there being 
more than twice the proportion of stover with the thickest 
planting as compared with the minimum ratio (11,880 
kernels). The comparative analysis of stover and grain 
as summarized by Jenkins and Winton is given in the 
following table : — 



184 



CORN CROPS 



TABLE XLVII 

Composition of Stover and Grain in 

Basis 



Corn. Water-free 













Nitro- 






Number 


Ash 


Protein 


Fiber 


gen-free 


Fat 




OF 


Per- 


Per- 


Per- 


Extract 


Per- 




Analysis 


centage 


centage 


centage 


Per- 
centage 


centage 


Fodder . . . 


35 


4.7 


7.8 


24.7 


60.1 


2.8 


Leaves . 


17 


7.9 


8.6 


30.6 


51.0 


1.9 


Husks . . . 


16 


3.5 


5.0 


32.2 


57.9 


1.4 


Stalks . . . 


15 


3.6 


5.9 


34.8 


64.1 


1.6 


Stover . . . 


60 


5.7 


6-.4 


33.0 


53.2 


1.7 


Grain . . . 


208 


1.7 


11.7 


2.4 


78.1 


6.1 



In well-developed corn planted at proper distance for 
maximum yield, the weight of shelled corn will be almost 
equal to the weight of stalk. Increasing the rate of 
planting has very little effect on the composition of either 
grain or stalk, but, as the proportion of stalk to grain 
increases, it is evident that the analysis of the whole 
plant will show a decreased percentage of protein and fat 
and an increased percentage of fiber. The total protein 
per acre, however, will increase. Silage from very thickly 
planted corn will not be so rich in percentage of protein 
and fat, but the total yield per acre will be greater. 

By reference to Table XLIV it will be seen that the rate 
of planting has more effect on percentage of ears in a dry 
season than in a seasonable year. The same would be true 
on poor soil. 

CHOICE OF A VARIETY 

131. There are probably one thousand named varieties 
of corn. This very large number of varieties, many of 
1 U. S. Dept. Agr., Office Exp. Sta., Bui. 77. 1892. 



PREPARATION- AND PLANTING 185 

which are of only local importance, makes rather confusing 
a study of experiments, in order to select the best varieties. 
In some cases a number of varieties have had a common 
origin and for a general discussion might be grouped to- 




FiG. 52. — Rou^h division of the United States into corn regions, accord- 
ing to the types of corn grown. 

gether. There are other groups, originating from widely 
different sources, which are yet very similar for all practi- 
cal purposes. 

The eastern half of the United States, where most of 
the corn is grown, may be roughly divided into large 



186 CORN CROPS 

regions, within which certain types and varieties pre- 
dominate to a greater or less degree. 

Elevation must always be considered in selecting a type. 
For example, the coast plains of North Carolina would 
probably require a type similar to that suitable to the Gulf 
States, while the mountain regions would require a type 




Fig. 53. — Prolific varieties of corn produce from two to six ears per stalk. 
They are adapted principally to the cotton belt. (Cockes' prolific.) 



PREPARATION AND PLANTING 187 

normally adapted to a region as far north as Ohio. Thus, 
in North Carolina, above 2800 feet, flint varieties are 
recommended — the type of corn most common in the 
New England States. Other local considerations enter 
in, but in general the following varieties have been found 
satisfactory in the regions indicated : — 

Natural divisions 

Section No. 1. Gulf States. Prolific varieties bearing 
160 to 200 ears to 100 stalks, on the average, give better 
results than those bearing only single ears. Typical 
varieties of prolific corn are : — 

Mosby Sanders Albemarle 

Cocke's Prolific Blount Marlboro 

Large-eared varieties are : — 
St. Charles White Boone County White 

Section No. 2. In this region large single-ear varieties 
share about equal importance with prolific varieties. 
In addition to the prolific varieties named above, we find 
such varieties succeeding as : — 

For good fertile land : — 

Boone County White St. Charles White 

Huffman White Pearl 

Leaming Hickory King 

For poorer soils and upland : — 

Hickory King Sanders 

Leaming St. Charles White (Early 

Strains) 
For high elevations : — 

Eight-row Flint 



188 



CORN CROPS 



This region partakes about half and half of the varieties 
common to the regions north and south of it. 

Section No. 3. This is the " corn-belt." Only large 
single-ear dent varieties are grown. South of this belt 
the dent com is mostly white in color, but in the corn- 
belt yellow corn is as popular as white. Typical varieties 
are : — 



Yellow 
Leaming 
Ried's Yellow 

Dent 
Riley's Favorite 
Legal Tender 



White 
Silver Mine 
Boone County 

^Vhite 
Johnson County 

White 
St. Charles White 



Early varieties 
Pride of the 

North 
Early Calico 
White Cap 



Leaming is probably the most extensively cultivated 
corn in the United States, being not only a universal 
favorite as a field corn, but also grown extensively for 
silage corn. Silver Mine is probably second in impor- 
tance. 

Section No. 4. This is more of the nature of a small- 
grain region, but corn culture is increasing. A few years 
ago flint corns predominated, but in recent years early 
dent corns have been developed and have largely replaced 
the flints. Typical varieties are : — 

Dent varieties Flint varieties 

Pride of the North King Philip 

Minnesota No. 13 Smut Nose 

Wisconsin No. 7 Eight-row Yellow 

Early Huron Hall's Gold Nugget 
White Cap 

Section No. 5. Flint corns are grown principally, 
though on the best soils below 1000 feet elevation, the 



PREPARATION AND PLANTING 



189 



early dent varieties share about equal popularity with 
the flints. Above 1000 feet elevation, flints are almost 
universal. Typical varieties are : — 



Flint varieties 
Eight-row and Twelve-row 

Yellow Flint 
King Philip 
Canada Smut Nose 
Hall's Gold Nugget 



Dent varieties 
Pride of the North 
White Cap 
Early Huron 

Various acclimated local 
varieties 



In this section, one-third to one-half of the corn is 
grown for silage. For this purpose the seed is usually 




Fig. 54. — Four ears in center are Sanf ord white flint, the longest type of 
cultivated corn. On right and left are shown typical ears of dent and 
flint, for comparison. 



190 CORN CROPS 

purchased and large varieties are used that do not ripen 
grain but are barely mature enough for silage when frost 
comes. Leaming, Hickory King, Eureka Ensilage, and 
other late varieties were extensively used in the past, 
but this custom is changing in favor of native grown dent 
and flint varieties. The native corns yield less stalk but 
more ears, making better silage. 

The importance of using acclimated seed has already 
been pointed out (page 117). AccUmated native seed 
should always be used for grain growing ; and even for 
ensilage, while it is not necessary that the grain should 
mature, a better quality of silage is secured if the climatic 
change is not too great. 

PREPARING SEED FOR PLANTING 

132. In the more humid part of the Corn Belt, corn is 
very likely to decrease in germination. This necessitates 
some precautions in curing the seed corn. In regions 
where the fall and winter climate is clear and compara- 
tively dry, there is less difficulty, but abnormal conditions 
occur often enough to justify special care of the seed corn 
as a regular practice. 

CAUSES OF POOR GERMINATION 

133. Slow or imperfect drying of the mature corn, 
often accompanied with freezing, seems to be the prin- 
cipal cause of deterioration of vitality in the germ. When 
corn is first " ripe " the kernels will usually contain about 
30 per cent moisture. This would be about September 15 
to October 1 in the Northern Central States. If the 
weather is dry and favorable, the grain should dry down 
to about 20 per cent moisture in the course of four to six 



PREPARATION AND PLANTING 



191 



weeks. If the climate is fairly dry, the corn should then 
remain in a good germinating condition either on the 
stalks or in good dry storage. 

The principal cause of loss in vitality seems to be failure 
to dry out properly upon becoming ripe. It is not 
necessary for the 
corn to be frozen 
to lose vitality, as 
it deteriorates at 
ordinary tempera- 
tures during the 
three months fol- 
lowing maturit}' if 
not fairly dry. If 
freezing occurs, the 
loss is increased. 
A freezing tempera- 
ture occurring when 
the grain still con- 
tains a high per- 
centage of moisture 
may practically de- 
stroy vitality. 

Any cause that 
delays the proper 
drying of the corn 
after maturity will 

result in poor seed ^^.^^^^ or root of young plant." . \ 

corn. In many \ 

cases, growers are using varieties too late in maturing or 
not well accHmated. Deep-kerneled types are more 
likely to lose in vitality than shallow-kerneled corn. 
Varieties with large, sappy cobs are always slow in drying. 




Fig. 55. — Corn kernel split to show germ, 
whiqh is the dark-colored body within the 
white, and extending nearly the length of 
the kernel. The main outer part of the 
germ is the Scutellum, secretes an enzyme 
that reduces the starch for use of young 
plant. The column-like body in the upper 
half is the Plumula, develops into young 
plant. The body at the lowest point is the 
Radicle, or root of yoimg plant. . 



192 CORN CROPS 

STORING SEED CORN 

To insure good seed corn, the ears should be collected 
as soon as mature and dried. Methods of drying are 
discussed elsewhere. 

GERMINATION TESTS 

134. If seed corn has been properly saved, there will 
be no occasion for making more than a general germina- 
tion test. It is much cheaper to save the seed properly 
than to make germination tests. Whenever seed is to be 
selected from a supply, the quality of which is doubtful, 
careful germination tests should be made. 

The general test 

135. A general test should be made first. Choose 100 
ears at random and remove three kernels from each at 
different parts of the ear, as butt, tip, and middle. 

A good germinater is made by using two pie tins or 
dinner plates. Fill one with sand, sawdust, or soil. Place 




Fig. 56. — A simple germinater for testing seed corn. The corn is placed 
between damp cloths or blotters. 

a cloth on this and spread out the kernels to be germinated. 
Place a second cloth over the seeds and wet down. Then 
invert the second pie tin or dinner plate over the first 
so as to make a moist chamber within. 'Keep moist and 
in a warm place. Six days is sufficicDt time to allow for 
germination. If 90 per cent or more of the seeds show 
good strong sprouts, it is doubtful if it would pay to make 
a germination test of each ear separately. 



PEEPARATION AND PLANTING 



193 



The ear test 

136. When the preliminary test shows germination to be 
low or a high percentage weak, it will pay to germinate 
each ear separately. 

There are several " seed testers " on the market adapted 
for this work, but satisfactory germinaters can be made 



Ml 









-.::m^m 






Fig. 57. — Making a germination test. The rack contains 100 ears, cor- 
responding in number to the squares in the germination box. 



at home. Usually a series of shallow trays are made and 
filled with sawdust or sand. A cloth is laid on top 
marked off in two-inch squares, and each square is num- 
bered. Twenty inches square is a convenient size, though 
some prefer a tray twice to five times as large. The ears 
to be tested are laid out on shelves in sets of ten. The 
ears are then taken in order, six grains removed, and these 
grains placed in the corresponding square on the cloth. 



194 



CORN CROPS 



It is well to take two kernels from the butt, two from the 
middle, and two from the tip, of the ear. When a tray 
has been filled, the grains are covered with a second 
cloth and a little sawdust on top and thoroughly wet down. 
When all trays are filled they are stacked up m a warm 
place and wet once a day for five or six days. All ears 
that have not shown a strong germination by this time 
should be discarded. 



IMPOKTANCE OF STRONG VITALITY 

137. It should be emphasized that only ears showing a 
strong, quick-growing germ should be used. C. P. Hartley 
records a typical experiment illustrating this point.^ 













Fig. 58. — Difference in germination of ears. In each square are six 
kernels, each from a different ear. 

1 Hartley, C. P. The Seed Corn Situation. U. S. Dept. Agr., Bur. 
Plant Indus., Circ. No. 95. 1912. 



PREPARATION AND PLANTING 



195 



In November two bushels of seed corn were selected, one 
bushel being placed in a corn crib and the other in a dry- 
seed room. Germination was about equally good in both 
cases, but the plants from the seed kept in the dry house 
were stronger and the yield averaged five bushels more 
per acre. 

GRADING SEED 

138. The corn planter cannot be adjusted to uniform 
dropping of seed unless the kernels arc uniform in size. 





^^^^m 


i 


■■'. ■<""'«*- '. - 


'V^^i^^^l 


^ 


r 


fl 




k''^' 


H 


■>■-■- _ «<•' 


Blip. 



Fig. 59. 



Three rows on left from single ear of good seed corn. Three 
rows on right froni single ear of poor seed corn. 



Some growers sort the seed ears into two or three lots, 
according to size of kernel. In some cases " sorters " 
are used, consisting essentially of a pair of screens that 
take out both the extra large and the extra small kernels. 



CALIBRATING THE PLANTER 



139. The dropping devices on planters are of three types, 
known respectively as (1) round hole drop, (2) round hole 



196 CORN CROPS 

accumulative, and (3) edge drop accumulative. The 
first type represents the earliest type of dropper plate, 
when it was attempted to regulate the number of kernels 
per hill by the size of hole in the dropper plate ; the hole 
being large enough to take two, three, or four grains 
at a time. In both the accumulative drop forms, the hole 





Edge Drop Flat Drop 

Fig. 60. — Two types of planter plates for dent corn. The edge drop is 
considered best where the corn is sorted to uniform size, and flat drop 
where the seed is not uniform. 

is large enough to take only one kernel at a time, the 
desired number of kernels being accumulated one at a time 
in a pocket and then dropped. The latter method is 
considered more nearly accurate when the seed has been 
well sorted. Before starting to plant, care sould be 
taken to see that the dropper-plate holes are of the right 
size for the seed used. 



CHAPTER XVII 
THE PRINCIPLES OF INTERCULTURE 



TILLAGE MACHINERY 



A GREAT variety of tools has been developed especially- 
adapted for the tillage of corn. For the first cultivation 
of drilled or checked corn, the common smoothing harrow 
is often used. It is an excellent tool for this purpose as 




Fig. 61. — The weeder. A very useful tool on loose soil, for cultivating 
corn the first four weeks. Cultivates three rows at a time. 

it works a wide swath and kills young weeds effectively. 
One disadvantage is that it carries considerable trash es- 
pecially where there are many large corn stubbs in the 
land. In this case the weeder is much better than the 
spike tooth harrow, as it clears of trash and does less in- 
jury to the young plants. When the weather is dry and 

197 



198 CORN CROPS 

the plants tough, aweeder may be used until the corn has 
reached the height of twelve inches. 




Fig. 62. — The simplest typ(> oi one-row cultivator, in extensive use 
throughout the corn belt. 

The corn cultivator has undergone a rapid evolution in 
the past fifty years. The first horse cultivators were single 




Fig. 63. — A modern riding corn cultivator, with handy adjustments and 
attachments, to readily adapt for all kinds of corn cultivation. Disk 
gangs attached. 



THE PRINCIPLES OF INTERCULTURE 



199 



shovel plows, consisting of a very broad mold-board 
shovel mounted on a beam, with handles to guide. Later 
two narrower shovels were substituted for the single broad 
shovel. Though this was an improvement, it was still nec- 
essary to go twice in each row for thorough cultivation. 





Fig. 64. — Spriiif^-tooth attachment. 





Fig. 65. — Shovel attachment. 



Fig. 66. — Cut showing 
angle and tilt adjustments. 



Later two of these double shovel plows were rigged on a two 
wheel sulky, thus enabling the operator with two horses 
to cultivate both sides of a row at one time. The corn 
cultivator is still built essentially on this principle with 



200 COBN CROPS 

many types of shovels and improvements for ease in con- 
trolling as illustrated in Figs. 63-66. 

Modern cultivators may be fitted with four to eight 
shovels, the size of the shovels decreasing as the number in- 




"FiG. 67. — Two-row corn cultivator for three horses. 

creases. The six or eight shovel type is usually preferred 
where the ground is in good tilth and the weeds small. 

Where the ground is hard and the weeds large, so that 
the land must be plowed rather than cultivated, the 
large four shoveled type is more effective. On stony 
land the spring tooth gang is often preferred. Also 
most standard riding cultivators may be fitted with disk 
gangs. Disk cultivators do excellent work in the hands 
of a skilled operator. They are especially desirable when 




201 



^02 CORN CROPS 

the soil is in poor physical condition and needs pulver- 
izing. 

Two-rowed cultivators adapted for use with either two 
or three horses are now in general use. If two-row cul- 
tivators are to be used, the rows should be straight and 
uniformly equal distances apart. With the two-row 
cultivator it is not possible to do as careful work close to 




Fig. 69. — Late cultivation of corn, with narrow tooth plow. 

the row as when a single row is worked at a time. On 
the other hand, when the corn is clean in the row it may 
do all that is necessary in half the time. 

One horse cultivators are not used much in corn cultiva- 
tion, except occasionally for late cultivation where the 
plants are too high to straddle. 

For listed corn sl variety of tools has been specially 
devised. A spike tooth harrow is often used to level the 
ridges slightly when the corn first comes up. Then a 
tool such as illustrated in Fig. 70 is sometimes used or, 
more commonly, a two-row tool of the type illustrated in 
Fig 71. The first time over, the disk followers are usually 



THE PRINCIPLES OF INTERCULTURE 



203 



set to throw out, as shown on the right of the figure, with 
a shield to protect the young corn and a pair of small 




Fig. 70. — Tool for cultivating listed corn the first 
time over. 

shovels to work in the bottom of the furrow. Later the 
disks may be set wider apart and set to throw toward 




Fig. 71. — Two-row listed corn cultivator. 



the corn. The shovels may be adjusted to suit con- 
ditions. 





KM 






F'' 
s;*.^' 




1 


^.-■'f ■■■■••■ « 


* 




'^f^ ^ ''W'J*!- fc^ ■'■^^^'' 









204 



THE PRINCIPLES OF INTERCULTUEE 205 

140. Jethro Tull said, " Tillage is manure," and this 
axiom has been more cr less accepted and inculcated into 
our theories regarding the interculture of hoed crops. In 
the case of small grain crops, which are sown thickly 
enough to fully occupy the land, benefit has rarely been 
derived from interculture. With crops which are planted 
wide apart and which never fully occupy the intervening 
ground, it has been found profitable to give sufficient 
interculture to prevent the growth of weeds. 

How much more interculture may benefit the crop than 
by keeping down weeds is a debated question. Various 
reasons have been advanced to account for the benefits 
of interculture and these may be summarized as follows : 

To destroy weeds. 

To conserve moisture. 

To reduce run-off of rainfall by keeping the surface 
loose and porous. 

To aerate the soil. 

To increase availabiUty of plant food. 

The relative importance of each of the above functions 
of interculture will vary according to locality and season. 
Interculture to aerate the soil and to free fertility may be 
important on certain heavy clay soils in a humid region, 
but negligible on more porous soils or in a dry region. 
Where torrential rains occur during the growing season, 
it is important to have the surface in a porous, granular 
condition. 

In general, however, the conservation of moisture and 
the destruction of weeds are properly advanced as the 
principal objects of interculture. Of all objects, the de- 
struction of weeds appears to be paramount. This con- 
clusion is arrived at as the result of numerous experiments, 
which have shown that keeping down weeds by shaving 



206 



COEy CROPS 



off has given almost as good results as when the soil was 
given good cultivation. 

METHODS OF TILLAGE COMPARED 

141. In the following tables are shown the results of 
three of the above-mentioned experiments under very- 
different climatic and soil conditions, namely, New Hamp- 
shire, Illinois, and Utah. All give the same general con- 
clusion — that culture beyond the destruction of weeds 
has not given much increased yield. 



TABLE XLVIII 

Results at Three Stations with Different Methods of 
Cultivating Corn. New Hajvipshire Station (Bul. 71, 
1900) 



Kind of Culture 


Yield 
Bushels per Acre 


No culture, weeds permitted to grow . 

Shallow, 14 times 

Shallow, 5 times (ordinarj^ culture) . . 

Deep, 5 times 

Mulch, covered with swamp hay . . . 


17.1 
80.6 
79.1 
69.7 
56.1 



Illinois Station (Bul. 31, 1894) 





Average Yield for 


Kind of Culture 


Five Years 




Bushels per Acre 


None, weeds scraped with a hoe 


68.3 


Shallow, about four cultivations . . . 


70.3 


Deep, about four cultivations .... 


66.7 


Shallow, about eight cultivations 


72.8 


Deep, about eight cultivations .... 


64.5 


None, weeds allowed to grow .... 





THE PRINCIPLES OF INTERCULTURE 207 

Utah Station (Bul. 66) 



Kind of Culture 


Average Yield for 

Eight Years 
Bushels per Acre 


None, weeds pulled by hand 

Scuffle hoe (scarified) 

Shallow tillage, 1\ inch 

Medium tillage, 2\ inches 

Deep tillage, 3| inches 

Mulched with soil 


51.8 
58.8 
52.9 
57.3 
57.4 
55.8 



It has been shown by numerous experiments on bare 
soils that a mulch of straw or of dry loose earth would 
conserve considerable moisture. It has also been pointed 
out heretofore (page 87) that the need of water is the 
most common limiting factor in corn production. Rea- 
soning from this, it seems that interculture should play 
an important part in conserving moisture and this increas- 
ing yield, but practical experiments fail to show such 
increases. 

WATER-LOSS FROM FALLOW SOIL 

142. For three months (April, May, and June) the 
prospective cornfield is essentially a bare field, exposed to 
wind and sunshine; and it is to be expected that early 
plowing and maintenance of a soil mulch will conserve 
moisture during this period. 

At the Wisconsin station adjacent plots of land were 
plowed in early spring seven days apart. During this 
interval of seven days the unplowed plot lost 1.75 inch 
of water, while the plowed plot had actually gained mois- 
ture in the first 4 feet, probably due to capillary water 
from below. 



208 CORN CROPS 

Widstoe^ states that " Fortier, working under Calif ornia 
conditions, determined that cultivation reduced the evap- 
oration from the soil surface over 55 per cent." At the 
Utah station similar experiments have shown that saving 
of soil moisture })y cultivation was 63 per cent for a clay, 
34 per cent for a coarse sand, and 13 per cent for a clay 
loam. 

EVAPORATION UNDER CORN CROP 

143. When the corn becomes large enough to shade the 
ground, which will be soon after the time that interculture 
begins, most of the conditions causing loss of soil moisture 
in fallow soils will have become to a large degree ineffec- 
tive. Wind, the most potent cause of soil drying, is 
almost nil at the soil surface ; direct sunshine is cut off, 
the soil being in shade part of the time ; and humidity is 
higher. At the Nebraska station, jars of w^ater set in 
wheat fields level with the soil surface lost practically no 
water. 

Another important factor in preventing loss of soil 
water by evaporation is the spread of roots near the sur- 
face. (See page 27.) If there is no rain, practically all 
water moving upward from the subsoil is intercepted by 
these roots and used by the plants. If there is rain, the 
surface moisture is soon reduced by the surface roots to 
a point where upward capillary movement is retarded. 

From the above, it appears that interculture of the 
corn crop can do very little toward conserving moisture. 

THE EFFECT OF WEEDS 

144. A crop of weeds will not only take out moisture, 
but also consume available plant food. As plant food in 

iWiDSTOE, John A. Dry Farming, p. 155. 



THE PRINCIPLES OF INTERCULTURE 209 

available form is usually more limited than the water 
supply, the consumption of plant food by weeds may be 
even more injurious than the consumption of water. Only 
when water and fertility are far in excess of the needs of the 
crop could weeds do no harm. 

The effect of witch grass in reducing yield is illustrated 
by data obtained at the New Hampshire station (Bulletin 
71, page 55). Two plats of corn were treated in the same 
manner and given good cultivation up to June 10. One 
plat was hand-hoed four times after this date in order to 
destroy the witch grass, while this was allowed to grow 
in the other plat. 

TABLE XLIX 
Effect of Witch Grass in Corn 



Kind of Culture 


Pounds of Corn 
Stover 


Bushels of Shelled 
Corn per Acre 


Hoed 

Unhoed 


11,843 

9,188 


81.6 
61.4 



We may conclude that, for corn, the principal -object 
of intertillage is to destroy weeds, and after this is accom- 
plished, further tillage will not pay. 

The above does not apply to small tilled crops, as vege- 
tables where the soil is exposed and the roots do not fully 
occupy the surface soil. Here conditions approach those 
obtaining on fallow soil. 

DEPTH AND FREQUENCY OF CULTIVATION 

145. Since intertillage in corn apparently serves no 
important function beyond subduing weeds, it is to be 
expected that no increase in yield will result from culti- 



210 CORN CROPS 

vating more deeply or more frequently than is necessary 
in order to accomplish this purpose. 

In TableXLVIII are shown results at the New Hamp- 
shire, Illinois, and Utah stations with deep and shallpw 
tillage. The Illinois ^ results with methods of cultivation 
may be summarized as follows : — 

TABLE L 



Kind of Cultivation 



Frequent (4 plats) 
Ordinary (4 plats) 
Shallow (4 plats) . 
Deep (4 plats) 



Average Yield 

FOR Five Years 

Bushels per 

Acre 



68.6 
68.5 
71.5 
65.6 



The principal injury of deep cultivation is that roots 
are destroyed. The depth to which the soil can be 
stirred without injury to roots depends on the soil to some 
extent. (See page 28.) In humid regions and clay soils, 
perhaps 2 inches is the limit ; in loose loam soils in drier 
regions, the roots are ordinarily 3 inches below the surface ; 
while with listed corn, the cultivation may often be as 
deep as 4 inches. The roots are usually shallow next to 
the plant and deeper midway between rows. 

It is doubtful whether it would be an advantage to give 
deep culture, even when it could be done without particular 
harm to the roots, as illustrated with listed corn at the 
Kansas station. 

Roots of listed corn are deeper than surface planted 
corn, and there would be little injury from deep culti- 
vation. 

1 lU. Agr. Exp. Sta., Bui. 31 : 356. 



THE PRINCIPLES OF INTERCULTURE 



211 



TABLE LI 

Results at Kansas Station with Deep and Shallow Cul- 
ture FOR Corn. Average for Four Years (1892- 
1896).! 



Treatment 



Listed, deep culture 

Listed, shallow culture 

Surface planted, deep culture .... 
Surface planted, shallow culture . . . 
Surface planted, deep and shallow culture^ 
Surface planted, surface culture .... 



Average Yield 
Bushels per Acre 



29.7 
29.3 
27.3 
27.0 

28.1 
23.0 



In Table XL VII I are also given results with frequency 
of cultivation. The following data from the Kansas sta- 
tion further illustrate : ^ — 

TABLE LII 





Times Cultivated 


Two-year Average 


Times Cultivated 


Two-year 


Yield in Bushels 




Average 


PER Acre 


Three times a week . . . 


17 


24.8 


Twice a week . „ . . . 


13 


27.2 


Once a week 


7 


27.8 


Once in two weeks . . . 


4 


25.2 


Once in three weeks . 


3 


24.0 


Once in four weeks . . . 


2 


16.9 



We may therefore conclude, from the data presented, 
that up to the time when corn shades the ground, and the 

1 Kansas Bui. ^4 .-233. 

2 Deep first cultivation and shallow later. 

3 Kans. Agr. Exp. Sta., Bui. 45 : 131. 



212 CORN CROPS 

field is comparatively fallow, cultivation conserves some 
moisture as in any fallow soil. After the corn crop is 
thoroughly established and a layer of surface roots inter- 
cepts capillary moisture from below, the principal service 
of cultivation is to destroy weeds. Weeds compete with 
the plant for both water and plant food. 

GROWING CORN FOR SILAGE 

146. The general discussion has thus far had in view 
the culture of corn for grain. The recommendations taken 
as a whole apply quite as well to growing silage corn. 
It is generally true that the best quality of silage is made 
from corn grown under conditions for producing the 
maximum grain crop. 

For grain it is necessary that the variety chosen should 
mature sound grain, but in the case of silage corn it need 
not mature. In the Southern States, and in practically 
all the Corn Belt States, perhaps the best silage variety 
is also the best standard variety grown for grain. In 
New England and on higher elevations in all Northeastern 
States, the most profitable silage variety will probably 
be too late to mature. At elevations of 1000 feet or more, 
seed may be secured at the same latitude but grown 500 
to 1000 feet lower elevation. The growing season of 
corn usually shortens about one day to each 100 feet 
increase of elevation. At lower elevations it will be neces- 
sary to go 200 to 300 miles south for late seed. Dent 
corns are usually preferred for silage, Leaming being 
perhaps the most popular dent variety for this purpose. 
At higher elevations very early dents, sweet corns, and 
in some cases flint corns, are best. 

As pointed out heretofore (page 179), the total weight of 
dry matter increases with rate of planting, but the propor- 



THE PRINCIPLES OF INTERCULTURE 213 

tion of ear decreases. In general, l^he best rate, yield 
and quality both considered, is about one-fourth to one- 
third thicker than would be necessary to secure maximum 
yield of grain under the same conditions. 

Drills are best where the corn is planted somewhat 
thickly, as for silage. Even where hill planting has been 
found best for grain growing, drill planting has usually 
given slightly larger yields of stover. The difference, 
however, is too small to be of much importance, and the 
method to be adopted is to be determined by convenience 
in tillage and harvesting. Where harvesting is by ma- 
chinery, drill planting is most convenient; but where 
harvesting is by hand, hills are preferred. 



CHAPTER XVIII 
ANIMAL AND INSECT ENEMIES 

The corn crop is more easily protected from its animal 
and insect enemies than most of the important crops. 
Of those insects that hve on the roots of com, practically 
all are effectively controlled by rotation. At present the 
com rootworm and root-louse do considerable damage 
throughout the corn-belt, wherever several corn crops are 
grown in succession on the same land. 

Rodents and birds do some damage every year, but 
are only considered seriqus, where corn is grown in small 
areas. The corn ear worm is difficult to control, but this in- 
sect seldom does serious damage except in the Southern 
States. 

BIRDS 

147. Crows give some trouble in regions where they are 
plentiful and the acreage of corn is comparatively small. 
They pull up the plants for a period of two weeks after 
the shoots appear, in order to get the kernels for food. 
Scarecrows or strings stretched with pieces of paper at- 
tached are effective in small fields. Coating the seed with 
coal tar is a deterrent, but not a complete preventive. 
The treatment consists in dipping a paddle in hot coal tar 
and stirring in the seed corn until every seed is coated with 
tar. The seed is allowed to dry and is then planted. 

RODENTS 

148. Small ground squirrels of several varieties dig up 
seed one to two weeks after planting. The coal-tar treatment 

214 



ANIMAL AND INSECT ENEMIES 215 

recommended for crows is often effective as a preventive. 
Poison is also used. The ordinary method of poisoning 
is to soak a quantity of corn in a strychnine solution and 
plant this a few days ahead of the regular planting, in 
parts of the field likely to be molested. Very often the 
squirrels come mostly from adjacent pastures or meadows, 
and a few rows of poisoned corn planted next to these will 
be effective. 

INSECTS 

149. The larvae of several insects are very injurious 
to corn under certain conditions. These may be grouped 
as : (1) Insects injurious to the roots. (2) Insects injurious 
to the young plant above ground. (3) Insects injurious 
to some part of the mature plant, as ear or leaf. (4) 
Insects that become abundant in cornfields only when 
corn follows corn year after year, as the corn rootworm. 
The remedy for this kind is rotation of corn with other 
crops. (5) There is another group, which injures corn 
only when it follows certain other crops. This includes 
the wireworm, which is often injurious the first and second 
years after grass sod. The grub worm is most often inju- 
rious after a clover sod. (6) Certain migratory insects, 
as the chinch bug, army worm, and stalk borer, which 
come in mostly from adjacent fields. The most important 
of these insects from an economic standpoint are here 
given, together with suggestions for their control : — • 

Cutworms 

Cutworms live on various kinds of grasses. The moths 
lay their eggs in late summer. These eggs soon hatch 
and the partially grown larvae live over winter in the 
ground. They live on vegetation again the following year 



216 CORN CROPS 

and pupate during May and June. The larvae feed prin- 
cipally during the night, cutting the young plants off near 
the ground. Late fall plowing usually destroys many of 
the larvae. Late planting will often avoid them, and 
when the regular planting is destroyed it is usually safe 
to depend on a late replanting to escape. Cutworms are 
poisoned by mixing one pound of paris green to forty 
pounds of bran. When applied with a drill the mass is 
moistened and dried, so as to cause the poison to adhere. 
When applied by hand, a quart of molasses is added to the 
mixture. 

Grvhworms 

These are larvae of the May beetles, or June bugs. 
The eggs are laid in June, mostly in grasslands, but more 
or less in all cultivated fields, especially if recently dressed 
with barnyard manure. The larvae live on decaying 
vegetable matter or roots, and often prove very destruc- 
tive in cornfields. 

No effective remedy has been proposed except in regions 
where listing is practiced. Listed corn is not injured so 
much as is surface-planted corn. 

Wireworms 

These are the larvae of the family known as " click 
beetles." The eggs are laid in the spring, in soil on grass- 
land. The larvae usually live two years in the soil, then 
pupate in July and August, and are finally transformed 
into beetles in about four weeks. The larvae both eat 
and bore the stems and roots of plants. No success- 
ful remedy has been proposed. When damage is expected, 
the corn may be planted more thickly, depending on thin- 
ning where the wireworms do not reduce the stand. When 



ANIMAL AND INSECT ENEMIES 217 

replanting a field injured by wireworms the new rows are 
planted midway between the old, leaving the old plants 
as food for the worms. 

Note. The above pests, cutworms, grubs, and wireworms, give most 
trouble on grass sod. They seldom give trouble after cultivated crops 
where clean culture has been practiced. 

There are two insects that are most troublesome where 
continuous corn culture is practiced — the corn rootworm 
and the root-louse. 

Corn rootworm 

There are two species, known as the Western and the 
Southern corn rootworm. The larvae are similar and 
work in the same wa}^ though the beetles differ in color. 
In early fall the female beetles lay about a dozen eggs in 
the ground near the corn roots. These remain over winter 
and hatch the next spring. The larvae are about the 
size of a pin and two-fifths inch in length, almost colorl'ess 
except for the head, which is yellow. They do most harm 
in July and August. Starting near the tip of a large root 
they bore inside the root, toward the plant. As they 
multiply rather slowly and as corn is their only host 
plant, the rootworms are serious only where the land has 
been in continuous corn culture for three or more years 
in succession. 

Corn root-louse 

Injury from the corn root-louse is very irregular, due 
no doubt to its natural enemies which ordinarily keep 
it in check. When unrestrained, however, it increases so 
rapidly that it may become very injurious in a short time. 
Usually its injury occurs in spots rather than over the 
whole field, due probably to local centers of infection 
from which it spreads rapidly. During the summer the 



218 COKN CROPS 

wingless females produce living young continuously, which 
in turn at the end of a few days also begin producing young. 
The lice live on the juices that they suck from the corn 
roots. Winged females occur occasionally, which estab- 
lish new colonies. In the fall both winged males and 
females appear. This last brood lays eggs which live 
over winter. Ants are often associated with plant lice 
and it is thought that they assist in protecting them and 
in caring for the eggs. 

No practical way of restraining the lice has been sug- 
gested, except that early plowing and clean, thorough 
preparation of the land will destroy to a large degree 
those present in the soil. 

The corn ear worm 

The ear worm is the larva of a moth. Two to seven 
broods are produced each year, depending on latitude, 
about four broods ])eing the average at the 40th parallel. 
It is the brood produced at silking time that is most 
injurious. The worms eat off the grains near the tip of 
the ear, not onh^ destroying directly considerable grain, 
but also opening a way for fungous diseases and ear rot. 

Grain weevils 

In the cotton-belt mature corn is seriously affected by 
com ear weevils. They attack the corn both in the field 
and in storage. The weevil is the larva of a small black 
beetle {Calandra oryzce). The beetles usually enter 
through the open husks at the tip of the ear or through 
worm holes in the husk. A long husk, fitting Qlosely over 
the tip of the ear, is an effective protection against weevils, 
both in the field and in storage. The use of, and develop- 



ANIMAL AND INSECT ENEMIES 



219 



ment of, varieties with good husk-protection is advocated 
for the Southern States. (For details see U. S. Dept. 
Agr. Bui. 708, and Farmers' Bui. 1029, 1918.) 

The European stalk borer 

This insect has recently (1917) made its appearance in 
the United States. The borer often causes considerable 
damage to corn in Europe. The insect attacks all parts of 
the plant above ground. The borer is the larva of a moth 
(Pyrausta nubilalis). The larva lives over winter in the 




Fig. 73. — Ear of corn showing corn smut. 



220 COBN CROPS 

stems and stubble and cobs of corn plants. In Europe 
the insect is apparently held in control by parasites or 
other natural controls, though often very destructive. 
Where natural enemies do not exist, the only control 
method known is to burn all infected material. The 
control is difficult, however, since it also attacks other 
large stemmed plants, as weeds or grasses. (For details, 
see Cornell Extension Bui. 31, 1919.) 

Migratory insects 

Chinch higs. — While chinch bugs breed in cornfields, 
the principal damage is due to migrating bugs from adja- 
cent grainfields after harvest. The migration of wing- 
less bugs is prevented by barriers, such as a dust mulch 
10 feet wide, harrowed every day to keep loose, or a plow 
furrow mth post holes every 2 rods where the bugs collect 
and may be destroyed by kerosene. A barrier of tar is 
sometimes used. 

Army worms. — Where army worms migrate, the 
remed}" generally recommended is to establish a post- 
hole barrier by plowing several furrows toward the colony ; 
in the bottom of the last furrow, dig post holes into which 
the army worms fall and are killed with kerosene. 

DISEASES OF CORN 

150. The diseases affecting com are the common com 
smut (Ustilago zeoe) and certain ear rots, the most serious 
of which is caused by a fungus known botanically as 
Diplodia zece. Other forms of ear rot are caused by species 
of Fusarium. Both these diseases live over on infected 
stalks and ears, producing spores abundantly the follow- 
ing spring and summer to infect the new crop. The only 
remedy is to gather up and destroy by fire. 



ANIMAL AND INSECT ENEMIES 221 

Several fungus diseases attack the roots, stalk and ear, 
causing rots or diseased tissue. The efifect of these or- 
ganisms is sometimes very serious. The fungus diseases 
known to attack the corn plant in this way are species of 
Gibberella fusarium, Verticilhum, Rhizopus, and Pseudo- 
monas. The diseases are carried either on the seed or on 
old corn-stalks left in the field. At least one of these 
diseases, Gibberella, is known to attack wheat, causing 
the common wheat scab. Wheat after corn, where the 
corn has been diseased, is likely to be attacked by scab. 

When primary infection takes place, i.e., the young 
seedling infected, the plant may reach only a few inches 
in height, and then die. The plant may, however, resist 
the disease sufficiently to reach a height of several feet 
and in many cases produce an ear. In secondary in- 
fection, the plant is less injured and will often bear a full 
sized ear. 

In badly infected plants the roots rot off, but when less 
infected the roots are only partly destroyed. Discolora- 
tion also appears on the stalk, especially near the lower 
nodes and shank of the ear. There are practically all 
degrees of injury, from plants entirely killed in early growth 
to cases where little or no injury is noticeable. 

The diseases appear to be carried commonly by infected 
seed. By making an ear germination test, the infected 
ears can usually be detected, as the rots and molds appear 
on the seedlings in the germinator. By an ear-to-row test 
it is also possible to eliminate infected strains. (For more 
detailed information see Indiana Bui. 224, 1918.) 

Diseased stalks and roots also carry the infection in the 
soil. Crop rotation appears to be the remedy for this. 

It is rarely that the loss from smut or ear rot will amount 
to 1 per cent. Occasionally serious loss occurs. 



CHAPTER XIX 
HARVESTING THE CORN CROP 

151. In the New England States, where corn culture 
first developed, it was the custom from the beginning to 
harvest the stalk as well as the ears. " Topping " was 
a common practice, the stalk above the ear being cut off 
for forage when immature, and later, when the ears had 
matured, these being " snapped " off and stored in barns 
to be " husked." 

With the opening up of the North Central and Western 
States, from 1840 to the present time, corn became an 
important article of commerce. The acreage of corn 
increased rapidly and, with little use for the stover, the 
custom of harvesting only the ears became general. 

In the Southern States, the corn area has never been 
extensive and a part of the forage has generally been saved. 
The custom of '' topping " and " stripping " has been 
more general in the Gulf States than in other regions. 

Corn has also been found to be the cheapest and best 
crop for silage ; in dairy regions throughout the North- 
eastern States, corn is grown principally for silage, the 
entire crop of large dairy regions being utilized in this 
way. 

In the Central and Western States, only a small propor- 
tion of the stalks are harvested for either silage or stover, 
but the practice of harvesting the entire plant is increas- 
ing. It is customary, when only the ears are harvested, 

222 



HARVESTING THE CORN CROP 



223 




224 



CORN CHOPS 



to turn the farm live stock into the fields during the 
winter months to eat what they will of the leaves, husks, 
and smaller parts of the stalk. 



TIME OF HARVESTING 

152. The object should be to harvest at such a time as 
to secure the maximum amount of digestible food. The 
total dry weight continues to increase up to the time of 
ripening, as shown by the following data : — 

TABLE LIII 

Increase of Dry Weight as reported by Three Stations 





Approximate 
Date 


Yield of Dry Matter per Acre 


Condition when 
Harvested 


New 

Yorki 

(Geneva) 

Pounds 


Michi- 
gan 2 
Pounds 


Kansas' 
Pounds 


Aver- 
age 
Pounds 


Percent- 
age of 
Increase 


Ears in silk . 
Ears in milk 
Ears in glaz- 
ing . . . 
Ears ripe 


Aug. 10-15 
Aug. 25 

Sept. 15 
Sept. 25 


3,000 
4,300 

7,200 
8,000 


3,670 
5,320 

7,110 

8,020 


6,868 

7,716 
9,548 


3,335 
5,496 

7,342 

8,523 


65 

33 

16 



1 Ann. Rpt. 1889. 2 U. S. Dept. Agr., Farmers' Bui. 97: 12. 

3 Kans. Agr. Exp. Sta., Bui. 30 : 181-207. 

At the time when corn is in tassel or in silk, less than 
one-half the dry weight has been developed. Increase 
in dry weight continues up to maturity. There was an 
average increase of 16 per cent from the time corn was 
glazed to time of maturity. There is an increase not 
only in total dry weight, but in all valuable constituents, 
as shown by the following data from the Michigan sta- 
tion : — 



HARVESTING THE CORN CROP 



225 



TABLE LIV 

Yield per Acre of Green Fodder, Dry Matter, and 
Nutrients 



Time of Cutting 


Green 
Fodder 


Dry 
Mat- 
ter 


Pro- 
tein 


Nitro- 
gen- 
free 
Extract 


Fat 


Fiber 


August 10 (tasseled) 
August 25 (in milk) 
September 6 (glaz- 
ing) 

September 15 (ripe) 


21,203 
25,493 

25,865 
23,007 


3,670 

5,320 

7,110 
8,020 


472.7 
576.0 

711.0 
696.9 


1,828 
3,212 

4,554 
5,356 


67.9 
143.1 

199.0 
242.6 


1,010 
1,148 

1,294 
1,413 



Not only does the total yield increase, but the quality 
improves with maturity. The large group of compounds 
under the head " nitrogen-free extract " are not all 
equally valuable for feeding purposes. Starch and the 
sugars are the most valuable and both increase in propor- 
tion as the plant matures, due to the development of ear, 
as shown by Jordan of the Maine station.^* ^ 



TABLE LV 



Augus.t 15, ears beginning to 

form 

August 28, a few roasting 

ears 

September 4, all roasting 

ears 

September 12, some ears 

glazing 

September 21, all ears glazed 



Percentage of 
Starch and Sugar 
in Nitrogen- 
free Extract 




Pounds of Starch 
-AND Sugar 

PRODUCED PER ACRB 



358.5 

1,172 

1,545 

1,764 
2,244 



Maine Agr. Exp. Sta., Bui. 17:4. 

U. S. Dept. Agr., Farmers' Bui. 97 : 12. 



226 



CORN CROPS 



RELATIVE PROPORTION OF PARTS 

153. Before considering the time and method of 

harvesting the whole plant, it will be well to note the 

relative proportion and value of the different parts of the 

corn plant at various stages of growth. The Michigan 

station has studied this subject and reported the following 

results : ^ — • 

TABLE LVI 

Percentage of Total Dry Matter in Leaves, Stalks, and 
Ears of Corn Plants at Four Stages of Growth (Mich- 
igan Station, 1896) 



Time of Cutting 


Percentage of Total Dry Matter 


Leaves 


Stalks 


Ears 


August 24 (in milk) .... 

August 31 

September 7 (glazing) . . . 
September 14 (ripe) . . . 


36.41 
33.63 
30.03 
21.77 


34.27 
25.52 
25.53 
31.91 


29.32 
40.85 
44.44 
46.32 



COMPOSITION OF PARTS 

154. The total dry weight alone does not give a com- 
parative statement of the relative feeding value of the 
parts of a corn plant. The leaves are very high in al- 
buminoids, while the stalks are low in these compounds. 
Pound for pound, leaves are about twice as valuable as 
stalks. A further study of the distribution of the princi- 
pal compounds of the plant at different stages of growth 
is reported as follows : — 

1 U. S. Dept. Agr., Farmers' Bui. 97: 9-12. 



HARVESTING THE CORN CROP 



227 



TABLE LVII 

Distribution of Albuminoids and Nitrogen-free Extract 
IN Leaves, Stalks, and Ears of Corn at Different 
Stages of Growth 





Albuminoids 


NiTROGEN-FKEE EXTRACT 




Leaves 


Stalks 


Ears 


Leaves 


Stalks 


Ears 


August 24 (in milk) 

August 31 

September 7 (glazing) . 
September 14 (ripe) 


52.50 
51.06 
42.71 
30.60 


10.00 
2.53 
5.19 

10.70 


37.50 
46.41 
52.10 
58.70 


38.50 
28.40 
20.50 
15.90 


17.50 
23.64 
25.30 
29.40 


44.00 
47.96 
54.20 
54.70 



The above tables show very clearly the shift in relative 
proportion of dry weight and important food constituents 
from leaves and stalk to ear, as growth progresses. From 
the data presented in the last five tables it would seem that 
corn should be allowed to stand until quite mature before 
harvesting, since the total yield and quality apparently 
improve. There are two considerations against this : 
the loss of leaves, and the fact that both leaves and stalk 
become less palatable with maturity. 



RELATIVE VALUE OF PARTS 

155. From the last two tables it appears that at the 
time the ear is in the " milk " stage, the relative dry 
matter is about equally distributed between leaves, stalks, 
and ears, although 40 to 50 per cent of the total nutrients 
are in the leaves alone. There is then a gain in ear until 
46 per cent of the dry weight and about 56 per cent of the 
nutrients are found in the ear. 



228 



CORN CROPS 



RELATIVE FOOD VALUE OF EARS AND STOVER 

At the time corn would be cut for silage or fodder, 
when the ears are glazed, about 40 per cent of the protein 
and 20 per cent of the nitrogen-free extract are in the leaves ; 
or, of the total food value of the plant at this time, approxi- 
mately 30 per cent is in the leaves, 15 per cent in the stalk, 
and 55 per cent in the ear. 

Armsby ^ compiled the data from four stations and cal- 
culated the yield of ears and stover to be as follows : — 

TABLE LVIII 



Station 



New Jersey (dent) . 
Connecticut (flint) . 
Wisconsin (dent) 
Pennsylvania (dent) 
Average . . . 



Ears 



4,774 
4,216 
4,941 
3,727 

4,415 



Stover 



4,041 
4,360 
4,490 
2,460 

3,838 



The above average shows that about 53 per cent of the 
crop by weight is ears; but the ears contain a higher 
percentage of digestible nutrients than does the stover, 
and a calculation of the digestible nutdents in the above 
shows about 63 per cent in the ear and 37 per cent in the 
stover. The above figures represent the distribution of 
nutrients at the time the stover is cut for forage, but do 
not indicate the final distribution of digestible nutrients. 
Fodder is usualty cut when the ears are glazed in order to 
save the valuable leaves, and about ten days before it is 
ripe. But during this period there is considerable trans- 
location of sugars and starch from the leaves and stem to 



Penn. Agr. Exp. Sta., Rpt. 1887. 



HARVESTING THE CORN CROP 229 

the ear, so that in the fully matured corn crop, under 
normal conditions, between 60 and 70 per cent of the 
digestible nutrients will be in the ears. 

This ratio would not apply to corn planted thick for 
silage, when the proportion of stover is increased with a 
decrease in the yield of ears. 

There is also considerable increase in total weight 
between the time the ears are glazed and the time when 
they are ripe, usually amounting to about 10 per cent. 
The value of stover obtained must be decreased by what- 
ever loss is occasioned by earl}^ harvesting. Charging 
this loss against the stover, it would appear that the total 
feeding value of the crop is increased about 25 per cent by 
harvesting the stover when the ears are glazed, in com- 
parison with allowing the crop to mature and harvesting 
only the ears. 

In conclusion, corn should be permitted to become as 
nearly mature before harvesting as is practicable. As 
pointed out heretofore (page 227), two-thirds of the value 
of the stover is in the leaves, and it is therefore important 
to save these. In a humid climate, with fall rains, it is 
often possible to allow corn to stand until most of the 
ears are mature before cutting ; but in a region with dry 
falls and windy weather the harvesting must be done 
seven to ten days earlier, if the leaves are to be saved. 

TIME OF HARVESTING FOR SILAGE 

156. When the silo first came into use, the custom was 
to use very immature material. It was found in time 
that silage from mature corn was better in quality and the 
yield was greater. There is a hmit, however, in this 
direction. Silage, in order to keep well, must pack closely, 




230 CORN CROPS 

and as nearly as possible, all air must be excluded. 

Corn too mature cannot be packed closely enough, 
though sprinkling with water and 
careful tramping will allow the 
ensilaging of corn even when more 
than half the ears might be con- 
sidered ripe. As a general rule, 
when the husks have mostly 
turned yellow, and two to four 
bottom leaves have turned, is the 

Fig. 75. — A modern silage ,. 

cutter, with blower at- Proper time. 

tachment, for delivering Good silage contains about 75 
the cut silage. ^^^ ^^^^ ^^^^^^ ^^^ .^ .^ ^^^^tful 

whether it would be practicable to ensile corn containing 
less than 65 per cent moisture. 



METHODS OF HARVESTING 

157. The four methods of harvesting maize are as fol- 
lows : — 

1. Stripping : leaves removed while green for forage, 
and ears husked later. 

2. Topping : tops cut off above ear for forage, and ears 
husked later. 

3. Ears only harvested, stalks left in field. 

4. Entire plant harvested for silage or fodder. 

Harvesting by hand 

158. Stripping and topping are practiced in the belief 
that in this way the forage may be obtained while 
green and in the right condition to harvest, while the 
ears are allowed to remain and mature. It has been 



HARVESTING THE CORN CROP 



231 




232 CORN CROPS 

shown/ however, that both stripping and topping reduce 
the yield of grain, so that it is doubtful whether the total 
yield of grain secured is greater than when the whole 
plant is harvested as fodder. The loss of shelled corn has 
generally amounted to 10 to 20 per cent, which is about 
the usual loss when harvested as fodder. 

The Texas station reports the labor expense of topping 
and stripping to be as follows : — 

Tops only: Cost per ton of dry-cured fodder . . . . $2.13 
Leaves only: Cost per ton of dry-cured fodder .... 7.67 

As it takes about four acres to produce a ton of leaves 
and half as much for a ton of tops, the value of the forage 
secured does not compensate for the loss of grain and 
cost of harvesting. 

159. Hand cutters. — Probably the first tool used in 
harvesting fodder was the hoe. Corn knives came into 
use in time, those made from old scythe blades being the 
most common at first.. Corn " hooks " were also made 
by inserting a short blade at about right angles in a short 
wooden handle. There are several standard types of 
knives and hooks on the market. 

Horse-drawn cutters 

160. The first horse-drawn cutters to have a general 
use were sleds, drawn astride of the corn row, with a 
heavy knife attached in front at the right height to cut 
off the corn plants, or drawn between two corn rows with 
a heavy knife attached to one or both sides for cutting 

1 Miss. Agr. Exp. Sta., Bui. 33: 63. 1895. 
Penn. Agr. Sta., Rpt. 1891 : 58-60. 
Ga. Agr. Exp. Sta., 23: 81-82. 1893. 
Ark. Agr. Exp. Sta., Bui. ^4; 120. 




>— ^ ^. 



J6- 


J<5 


J4 


c7c7 


28 


27- 


<S8 


<57 


iir js cJ9 


JO 


29 26 


69 <56 


J 2 / 


J/ J2 2,S 


60 


SJ 


4 


J 8 




2 J 22 


S4 


40 


6 7 


24 2/ 


20 


4/ 


46 


9 /6 /cf 


/Z /8 /9 


42 4d- 


/O /cJ 


/4 


cfj iS2 J/ 


4d 


44 


// 


/2 


47 


48 


49 


•SO 



Fig. 77. — A corn hook and knives used in harvesting corn fodder. A 
"horse" used in shocking corn fodder. A home-made sled cutter. 
The sled is drawn by a horse between two rows, the stalks being cut 
by sharp knives on each side. Two operators stand on the sled. 

The lower figure illustrates a system of cutting by hand, in order to 
economize steps. 

233 



2U 



COltN CROPS 



the plants. Later, wheels were substituted for runners 
and seats were provided for the men. Some cutters have 
iarge platforms to carry the green fodder until enough has 
been accumulated for a shock. There is no labor saved 




Fig. 78. 



A two-row corn cutter mounted on wheels. The two operators 
stand between the wheels. 



by having a large platform, and the most popular type 
is that in which there is room for only a large armful to 
be collected at a time. 



The corn hinder 

161. The first successful corn binders were introduced 
about 1895 and have steadily increased in popularity. 
The corn is bound in bundles of convenient size, and with 
a bundle carrier six to eight bundles may be collected 
before dropping windrows to be shocked up later or drawn 
to the silo. 



HARVESTING THE CORN CROP 



235 



Shocking corn 

162. The ordinary custom in curing fodder is to leave it 
in shocks for one to three months. It is then sufficiently 




Fig. 79. — Corn fodder harvester in section. 



cured to husk or store in barns or stack yard. It is 
often left in the field to be hauled as needed during 
the winter. 

Size of shocks 

163. The exposure and loss is greater in small shocks 
than in large. Where fodder is green, the shocks must 
be small if the corn is set directly into shock, ordinarily 
one hundred to one hundred fifty hills being enough. 
When cured it is often practicable to set two or three 
shocks together or to stack. When the fodder can be 
allowed to partly cure before shocking, as in harvesting 
with a binder, the shocks should be made as large as is 
practicable. 



236 



CORN CROPS 







HARVESTING THE CORN CROP 237 

Setting up shocks 

164. When cutting corn with knives, it is customary to 
tie four hills together for a '^ horse " in the place where it 
is proposed to place a shock. In other cases a " horse " 
is made as illustrated in Fig. 77. In setting up bundles 
after a corn binder, a " horse " is not necessary. 



Tying shocks 

165. After the shock is well set up, the tops of the out- 
side stalks should be tucked under and the shock securely 
tied with binder twine. A rope with iron hook on one 
end, or a quirt, is useful in drawing the shock before tying. 

When corn is cut by hand, some steps will be saved by 
following a systematic plan, in cutting the hills for each 
armful. Such a plan for a shock eight hills square is illus- 
trated in Fig. 77. 

Husking fodder corn 

166. The fodder may be husked in the field, a common 
practice in the West, or as common in the East, hauled 
to the barn to be husked later, or hauled to a shredder. 
The shredder delivers the shredded fodder and husked 
ears in separate piles. When husking by hand in the 
field the ears are often thrown into piles, to be collected 
later with a wagon. A more convenient way is to husk 
directh^ into the wagon. A high " throwboard " should 
be put on the wagon box opposite the husker. A light 
frame on wheels may be attached to the rear of the wagon 
across which the fodder corn is thrown for husking. This 
allows the husker to stand while at work. 



238 



CORN CROPS 



Shredding fodder 

167. Zinthco makes the following statement : ^ " Be- 
tween 1880 and 1890, a great deal of attention was given 
to threshing corn. This practice so battered the stalk as 
to make every part of it available as a cattle food. Fodder 
cutters had been in use for many years yet this method of 
preparing corn fodder left the fibrous part of the stalk in 
a tough woody condition which cattle did not relish. The 
bruising and shredding action of the thresher put the 
stalk in a more palatable form. The repeated shortages 
and failures of the hay crop during the decade 1880-1890, 




Fig. 81. 



ibined shredder and busker. 



together with the results of attempts at threshing corn, 
led to the invention of the combined husker and shredder, 
which takes the stalks with the ears on them and prepares 
the stalks for feeding." 

Shredding fodder is generally considered as an economic 
way of preparing corn fodder for feed. In humid climates 
there is sometimes trouble with the shredded fodder heat- 
ing when piled in large quantities, unless care is taken to 
shred only fodder in a fairty dry condition. 

1 U. S. Dept. Agr., Office Exp. Sta., Bui. 173:40. 



HARVESTING THE CORN CROP 239 

Hauling fodder corn 

168. When there is snow, a sled with fodder rack is 
most convenient. At other times and for drawing silage, 
a low down rack on wheels is desirable. 




Fig. 82. — Husking peg and husking hook. The peg is best for fodder 
corn and the hook for standing corn. 

Harvesting ears hy hand 

169. In the Corn Belt States, only the ears are harvested 
on perhaps nine-tenths of the area. The method is to 
husk directly into a wagon. A ^^ throw-board " about 
30 inches high is put on the wagon-box on the far side 
from the husker. The husker takes two row^s at a time and 
usually one man to a wagon. An average day's husking 
in good corn is 60 to 75 bushels of shelled corn. The 
husker uses a peg or hook in the palm of his hand to assist 
in tearing off the husks. 



240 



CORN CROPS 



Harvesting ears by machinery 

170. For at least fifty years, attempts have been made 
to devise mechanical corn pickers to operate in the field. 
Within the past few years, machines have been perfected 




Fig. 83. — Method of husking corn from the field in corn belt. 



HARVESTING THE CORN' CROP 241 

that do the work in a satisfactory maimer, provided the 
stalks stand up well and too many ears have not fallen 
to ground. At best, some ears are left in the field, 
which must be picked up by hand. In some cases, live 
stock are turned in to gather up ears that are left. As 
the machine requires six horses to draw it and two more 
teams to draw the ears away, it is only practical in large 
fields. A machine will husk about eight acres a day. 

Comparative cost of harvesting methods 

171. Zintheo ^ has collected and summarized data on 
comparative cost of different methods of harvesting corn. 
He gives the following estimate as comparative cost in the 
corn-belt, based on labor costs for 1906, where the corn 
is producing an average of 44 bushels per acre : — 

TABLE LIX 

Cost of Harvesting Corn by Various Methods 

Average data for harvesting by hand 

Cost of implement $1.00 

Acres one man harvests per day 1.47 

Cost of cutting and shocking $1.50 per acre 

Average data for harvesting with sled harvester 

Cost of implement . $5 to $50 

Acres 2 men and 1 horse harvest per day . . 4.67 

Cost of cutting and shocking $1.18 per acre 

Average data for harvesting with corn hinder 

Cost of implement $125.00 

Acres cut per day by 1 man and 3 horses . . 7.73 

Acres shocked per day, 1 man 3.31 

Cost of cutting and shocking $1.50 per acre 

1 Zintheo. Corn Harvesting Machinery. U. S. Dept. Agr., Office of 
Exp. Sta., Bui. 173: 46. 
R 



242 



CORN CROPS 



Cost per bushel of picking and husking corn 

CENTS 

By hand from field 3.5 

Team for cribbing 1. 

By hand from shock 5.3 

Team for cribbing 79 

By corn picker from field 4.1 

By huskers and shredder from shock . .4.5 

The relative cost of methods will differ, depending prin- 
cipally upon the price of labor. 



Storing ears 

172. The ears are usually stored in slatted cribs to 
provide ventilation. If a good roof is provided, there is 




Fig. 84 



A good type of farm corn crib, and farm eleva 
unloading. 



seldom loss from rotting in the crib. Rats and mice 
cause considerable loss where corn is stored for several 
months or more and it is important to have cribs rodent 



HARVESTING THE CORN CROP 



243 



proof. Ventilated sheet-iron cribs are now on the 
market, that are rodent-proof if set on a cement foun- 
dation. Wooden cribs can be made rodent-proof by Hn- 
ing with hardware netting or if constructed on a cement 
foundation. Where a cement floor and foundation are 
used, care must be taken to provide ventilation under- 
neath by means of a raised board floor. The floor may 
be slated and made in movable sections to faciUtate clean- 
ing beneath. 

Shrinkage in curing fodder and silage 

173. If the total dry matter and protein content of 
corn fodder be ascertained at the time of storage either as 
fodder or silage, it may be determined that there is a Con- 
stant loss in both for at least a year. The amount of this 
loss as determined by the Wisconsin station is summarized 
as follows : — 

TABLE LX 

Loss IN Curing Corn in Silo or as Fodder (Wisconsin 
Station, Three-tear Average) 



Method 


Green 
Fodder 
Pounds 


Silage or 

Dry 

Fodder 

Pounds 


Loss IN 
Pounds 


Loss in 

CrrEiNG 

Pounds 

Per Cent 


(a) Ensilage method 

Dry matter 

Crude protein . . . 
(6) Field cured 

Dry Matter . . . 

Crude protein . . . 


35,602 
2,910 

39,448 
3,102 


28,300 
2,312 

31,428 
2,619 


7,281 
597 

8,020 

482 


20.5 
20.6 

20 3 
15.6 



The Connecticut station ^ reports results of an experi- 
ment in which no loss was apparent while curing. Most 

1 Conn. Sta., Rpt. 1889 : 219. 



244 CORN CHOPS 

experiments, however, show field losses ranging from 10 to 
20 per cent. A part of this loss in field curing is due to 
direct loss of leaves and portions of the stalk. Where direct 
loss of material is entirely prevented, there is still a loss, 
apparently due to a slow process of oxidation or fermen- 
tation. This loss will go on even when placed in stack or 
under cover. 

As 15 to 20 per cent of the feeding value of corn fodder 
is in the leaves, a large share of the loss of field curing is 
due to loss of leaves, but a part to fermentations ; on the 
other hand, all loss in silos is due to fermentations. 

Gain in gross weight 

174. After fodder has become thoroughly air dry, its 
weight will then vary with the humidity of the air, as dry 
fodder readily absorbs moisture. The Connecticut sta- 
tion reports the results with two lots of fodder in 1877. 
The fodder-crop was very heavy, but the fall being dry, 
the two lots cured do\\ai to 27 per cent and 36 per cent 
moisture respectiveh^, when placed in the barn. The 
winter was warm and damp, so that 5.2 tons placed in the 
barn Nov. 11, had increased in weight to 8.5 tons by Feb. 8. 



Shrinkage of ear corn in storage 

175. When ear corn is stored as harvested in October 
or November, there is a shrinkage in total weight during 
the first year varying from 5 to 20 per cent. Shrinkage 
is principally due to drying out of water. It is directly 
related to how well the corn matures, and the dryness of 
fall weather. The following data from three experiment 
stations illustrate : — 



HARVESTING THE CORN CROP 



245 



TABLE LXI 

Shrinkage of Corn in Crib as summarized from Results 
OF Three Stations 



Month after Harvest 



December 
February 
March . 
April , 
June . 
August 
September 
October . 



Kansas 1^ 

Three- YEAR 

Average 

Per Cent 



3.26 

5.16 
6.80 
7.44 

8.62 



Illinois 2 

Four Trials 

Per Cent 



3.6 

5.7 

14.4 

16.6 



Iowa 3 
One year 
Per Cent 



8.7 
10.5 
16.2 
19.4 



1 Kans. Bui. 147 : 267. 2 m. BuI. 113 : 363. ^ jowa Bui. 45 : 228. 

Results at the Illinois station show practically no loss 
the second year. In fact after corn has become thoroughly 
air dry, the weight will then fluctuate with the humidity of 
the air, the variation amounting to as much as 3 per cent. 
(Seelll.Bul. 113, p.363.) 

Shrinkage is partly due to the loss of water, but as 
pointed out by Ten Eyck ^ the loss of moisture alone does 
not account for the entire decrease in weight. There is 
a decrease in actual dry matter probably due to some 
process of oxidation. 

Marketing 

176. Corn is usually marketed as shelled corn and is 
seldom shipped in ear. About 60 per cent of the corn 
crop is consumed on the farms where produced. About 
10 per cent is sold locally to feeders and about 25 per cent 

1 Kans. Bui. 147 : 268. 



246 ' CORN CROPS 

finds its way into the general markets. Of the total crop 
produced in the United States, about 3 per cent is ex- 
ported, hence a large share of the corn reaching the general 
market is redistributed in the United States. 

The ear corn is usually stored on the farm in cribs hold- 
ing 500 to 5000 bushels. When ready to market it is 




Fig. 85. — Large power corn sheller in operation on a farm. Will shell 
400 bu. per hour. 

shelled out, with power shellers that handle 200 to 400 
bushels per hour. The shelled grain is then hauled to a 
local elevator where it is loaded on cars and shipped either 
direct to a consumer, or to one of the large terminal ele- 
vators, where the grain may be stored. 

Drying corn for shipment 
177. Corn is comparatively easy to keep in storage, the 
principal difficulties coming from excess moisture. When 
corn is shipped in cars, from northern states to the south, 
or when loaded in ships for export, there is great danger 
that it Tvdll " go out of condition " if containing higher 
than 15 per cent moisture. Large commercial driers are 
now in general use, capable of drying several thousand 
bushels a day, to 12 per cent moisture. 



EABVESTING THE COEN CROP 



247 



Cost of 'producing 

178. The principal cost factors in producing corn are 
labor, and rent of land. The cost of seed and fertilizer 
being minor factors, at present, in the corn-belt, although 




Fig. 86. 



Large cement grain tanks, such as are used for storage at 
terminal markets. (Erie Railway, Chicago, 111.) 



in certain sections of the East and South, the use of fer- 
tilizers on corn is becoming more common. 

The rent of land is fairly well standardized, being in 
general about $5 per acre for land capable of producing 
40 to 50 bushels per acre. The amount of labor varies with 
soil. The required labor to produce an acre of corn on the 
heavy clay lands of the East is probably twice that 
required on the prairie land of Iowa and would be still 



248 



COBN CROPS 



less in central Nebraska and Kansas, where listing is a 
general practice. 

The cost of growing and harvesting ears from standing 
stalks has been reported from many sources, the general 
results being illustrated by the following data: — 



TABLE LXII 



Data from the Book 

OF Corn Bull. 48. 

Bureau of Statistics, 

Neb. Bull. 122 


Date of 
Investiga- 
tion 


Cost of 
Raising 

BY the 

Acre 
Dollars 


Cost of 

Har- 
vesting 
Ears 

FROM 

Standing 
Stalks 

Dollars 


Yield 

TO THE 

Acre 

Bush- 
els 


1 Total 
Cost 

Dol- 
lars 


Cost 
BY the 
Bush- 
el 

Cents 


Several states 
Minnesota (partly 
estimated) . . 
Nebraska . . . 


1897 
1902-04 
1909-10 


8.43 
/8.25 
\7.35 
10.06 


1.00 
3.51 
2.60 
1.59 


39.2 
40. 
40. 
39.3 


9.43 
11.76 

9.95 
11.62 


24.0 
29.4 
24.9 
29.6 





Earlier estimates when both land and labor were cheaper 
indicate that corn was produced for 20 cents per bushel in 
the period from 1885 to 1895. Data collected in 1909 by 
the United States Department of Agriculture showed an 
average cost for the United States of 37.9 cents a bushel, 
while in the two leading states, Illinois and Iowa, the cost 
was 31 and 30 cents, respectively. At present (1919), 
due to increased costs of production, it is generally esti- 
mated that cost of production has about doubled over 
1909. The fertility of land is an important factor in the 
cost per bushel or ton, as the expense of raising is little if 
any more on good land than poor. 

The cost of harvesting fodder corn and silage has been 
estimated in another place (page 241). 



CHAPTER XX 
USES OF CORN 

179. Perhaps nine-tenths of the corn crop is fed to live 
stock. The remainder is used in the arts, in manufac- 
turing glucose, starch, corn meal, breakfast foods, hominy, 
corn oil, and alcohol, etc. The' husks are used in mat- 
ting, the stalks and pith in packing, and corn cobs are 
used in making tobacco pipes. 

Corn meal and hominy have been important articles 
of food among American people from Colonial days. 
The use of corn as food has declined since the Civil 
War, probably due to the large production of wheat at 
low cost. The principal corn-meal market at present 
is in the Southern States, where it is extensively used 
by the people of both races. There is a general but 
light demand for '' fancy corn-meal " throughout the 
country. 

The two principal grades of meal are whole meal and 
" degerminated " meal. In the first case, the whole corn 
is ground and only the coarsest bran removed, giving a 
yield of about 94 pounds of meal from 100 pounds of corn. 
This meal contains all the germ which darkens the color 
and adds its own flavor. Within recent years, degerminat- 
ing has become general in making fancy meal. The germ 
and bran are all removed, the meal well ground and bolted, 
giving about 40 pounds of meal to a bushel of corn. 
This meal is often called " granulated " meal. 

249 



250 CORN CROPS 

Com bran and germ meal are the by-products of meal 
manufacture, both of which are used for stock food, while 
the germ meal is also used in the manufacture of prepared 
breakfast foods. 

Hominy is whole or cracked corn with the hull removed. 
Originally hominy was prepared by soaking the whole corn 
in a strong lye solution, which caused the hulls to loosen 
and was then removed by washing, but at present, the 
hulling of commercial hominy is done with machinery. 

Grits is coarse ground hominy, but the commercial 
product is usually prepared as an intermediate product 
in the grinding of meal. 

Germ meal is a by-product in the manufacture of corn- 
meal and starch and is composed principally of germs. 

Glucose or corn sirup is made by inverting the starch 
of corn by means of dilute hydrochloric acid. The 
germ is first removed and put on the market as germ 
meal or pressed to extract the oil. Gluten feed is the resi- 
due after glucose is extracted and is very rich in protein 
compounds and has a standard market value as stock 
food. 

Corn oil is extracted by pressure from the separated 
germs, which are about 30 per cent oil. The oil is used 
as a salad oil, in paints, or vulcanized as a substitute for 
vulcanized rubber. The residue after extracting oil is 
known as corn oil cake. 

Starch. — Corn was an important source of starch at one 
time, but potatoes are more commonly used at present. 
The starch is extracted by washing from the corn flour. 
A residue is left known as gluten feed. 

Distillery products are the residue left as a result of 
distilling alcoholic beverages. The starch is largely 
removed in distilling, leaving a fermented by-product, 



USES OF CORN 251 

high in protein content, which is put upon the market in 
various forms as stock food. 

Pop-corn products. — A large proportion of the pop-corn 
crop is utilized with no other preparation than popping, 
with a small amount of butter and salt added for seasoning. 
The popped corn is also used in various confections and in 
prepared breakfast foods. 

Siveet corn products. — The sweet corn crop is utilized 
as green corn on the cob, as " canned " corn, and " dried " 
corn. Dried corn was at one time an important home- 
made article of food and considerable was sold as a com- 
mercial product. Canning is the principal method of 
preserving green corn and has become an important 
commercial industry. 

Cereal food products. — Corn, either as grits, germs, or 
popped, is utilized to some extent in various prepared 
cereal foods. A common method is to cook the cracked 
hominy until soft, then roll into thin flakes, which are 
then dried. The cooking and drying increases the soluble 
sugars, and more or less carmelizes -the carbohydrates. 

Corn meal is utilized in various ways. Corn-meal mush 
and samp is made by simply boiling in water with a little 
salt, and is well known. Polenta, made in the same way, 
is said to be almost a national dish in Italy. 

The three principal forms of bread made from corn meal 
are hoe-cake, johnny-cake, and brown bread ; the formulas 
for which are given on the following page.^ 

In the " Cotton Belt " of the United States corn furnishes 
the principal bread food, rather than wheat. In other sec- 
tions of the United States — also in Europe — corn meal is 
used in proportions varying from 5 to 50 per cent in a variety 
of bread and pastry foods, where a coarse flour is desirable. 

1 Maine Bui. 131, p. 139. 



252 



CORN CROPS 





Johnny- 
cake 
Grams 


Brown 
Bread 
Grams 


Hoe-cake 
Grams 


Corn meal 

Flour (wheat) ...... 

Salt ......... 

Sugar . . 

Baking powder 

Molasses 

Water 

Milk 


100.0 
100.0 

5.0 
10.0 

4.4 

150.0 


100.0 

100.0 

4.0 

4.4 
40.0 

200.0 


100.0 

5.0 
5.0 

400.0 



References on corn as food : — 
Food Value of Corn and Corn Products. Farmers' Bui. 



1907. Indian Corn as Food for Man. 
1906. 



Maine Bui. 



298. 
131. 



CHAPTER XXI 
SHOW CORN 

The culture and characteristics of show corn deserve 
special discussion. 

180. Corn shows, in common with poultry and live stock 
shows, serve a practical purpose, in so far as they sustain 




Fig. 87. — Show ears of Boone County White. A typical white variety' 
of the corn-belt. 

interest, and serve as a rallying ground for those interested 
in production. 

On the other hand, show corn is not necessarily the best 
type to grow or most productive, and farmers have often 

253 



254 



CORN CROPS 









>^i^ 



t^C=? 



-?^g^ 



-^^F- 

^?^^l^ 






made the mistake of buying it 
to plant under conditions not 
suited to that type of corn. 

Usually show corn is grown 
under the most favorable con- 
ditions of climate and soil. 
There are certain regions, such 
as southern Indiana, central 
Illinois, and Missouri River 
bottom land, where corn appar- 
ently attains a perfection in 
type not possible under aver- 
age conditions. 

Our study of acclimatiza- 
tion developed the importance 
of growing seed corn under 
conditions similar in soil and 
climate to the region where 
it is to be used as seed. This 
makes it doubtful whether 
corn gro^n under the most 
favorable environment is best 
adapted for average conditions. 

The future of corn shows 
does not rest so much on 
practical considerations as 
aesthetic. A sound, perfect 
ear of corn is beautiful, artis- 
tic, and pleasing to the senses. 
The plant on which it grew is 
interesting in the same way. 

Fig. 88. — A typical ear of show corn. 
Ried's yellow dent. 






SHOW CORN 255 

The ear also represents the largest and most interesting 
crop in the United States, and the principal means of sup- 
port of many millions. So long as men admire perfect 
ears of corn, the corn show will last. 

181. Show corn is judged, on the basis of degree of 
perfection exhibited, both in soundness and general sym- 
metry, uniformity, and beauty. It must be perfectly 
sound and matured, and free from signs of deterioration 
due to disease or improper care. 

The characters of show corn may be grouped in two 
classes, as those that pertain to soundness and maturity 
and those that pertain to perfection in symmetry and uni- 
formity. The first class is of practical value and applies 
in the judging of all seed corn. The second class of points 
cannot be said to be important to consider in seed selection. 

182. Maturity is judged by the general plumpness and 
development of the kernels. If the kernels are loose on the 
cob, or unduly shrunken at tip or crown, the ear probably 
did not mature properly. 

183. Soundness is judged principally by the vitality 
of germs and strength of germination. Good germs 
should be plump, of a texture similar to good cheese, and 
no signs of discoloring. Any variation from this can 
usually be seen, but it is not always possible to judge 
the viability by examination alone. A germination test 
is sometimes necessary to determine this point. 

Fane?/ characters pertain to the perfection and sjmimetry 
of development of all parts of the ear, as butts, tips, rows, 
kernels, etc. 

184. Standards of perfection have been adopted in re- 
gard to a few of the best-known varieties, but at present 
these standards are not regarded very much by corn 
judges, but rather a universal standard has come to be 



256 CORK CBOPS 

recognized, which is apphed to all exhibits, more or less 
regardless of variety. 

For dent corn the following standards are generally 
accepted : 

Shape of ear. — Cylindrical or nearly so. The circum- 
ference should be about three-fourths the length. 

Size of ear. — The standard size of large dent varieties 
is ten inches in length and seven and one-half inches in 




Fig. 89. — Ideal butt and tip ends of dent corn. Note the regular size of 
kernels in both cases. 

circumference; of medium dents, eight inches long and 
six inches circumference. 

Rows. — The rows should be straight, and each row 
be full length of ear and extend well over butt and tip. 
Short or irregular rows are regarded as imperfections. 

Butt ends. — The butt end should be well rounded, 
not flat. The shank should be about one-half the diam- 
eter of cob. If smaller, the ear is liable to fall off the stalk ; 
and if larger, the ear is more difficult to husk. 

Tip of ears. — The rows should extend in a regular 
way well over the tip. Only a small exposure of cob at 



SHOW CORN 



267 



the tip end is allowed. Full depth of grain should extend 
almost to the very tip of the ear. 

Type of kernel. — A good kernel of large dent corn 
should be about seven-eighths inch in length and 
three-eighths in width, if 
an eighteen-row ear, but 
narrower if more rows. 
The kernels should fit close 
from tip to crown, being 
somewhat keystone shaped. 
The kernels should be fairly 
thick, averaging in the row 
about six kernels to the 
inch. The kernel tip should 
be full and square ; the germ, 

large, plump, and of good Fig. 90. — Cross-section of very 
1 111 deep-kerneled type of dent corn 

color and texture. commonly known as hackberry. 




GROWING SHOW CORN 

185. The seed must come from a good show strain 
with many generations of selection for type. The soil 
should be naturally good corn soil, and everything done 
to put the soil in perfect condition, by proper rotation, 
manuring, and tillage. The soil, however, can be too rich 
in nitrogen for best results, as the plant is then inclined to 
run too much to stalk rather than ear. The soil should 
be rich in available minerals. Good show ears seldom 
come from the portion of field where the growth is rankest, 
but rather from a part where growth of stalk is normal 
but ears large. 

The rate of planting should be rather thin, about two- 
thirds normal stand. 



258 



CORN CROPS 



The crop should be handled so as to insure a rapid 
normal growth throughout the season without a check. 




Fig. 91. — An example of prolific corn. 



CHAPTER XXII 
SWEET CORN OR SUGAR CORN 

Sweet corn is grown chiefly as a vegetable for table 
use, although the stover is usually harvested as forage for 
stock. Sometimes sweet corn is planted as a silage or 
forage crop. The development of sweet corn has been dis- 
cussed in another place (page 79) . 

186. Production. — The last statistical report is for 
the crop of 1909. In the eastern states the distribution 
is largely influenced by the large city markets and truck- 

SwEET Corn Acreage and Value in the United States, 
1909 AND 1918 



1909 Census Data 


Data for 1918 — 

Acreage Contracted 

BY Canners 


State 


Acreage 


Total Value 


Value 
per Acre 


Acres 


Tons 
per Acre 


New York . . 
Illinois . . . 
Maryland . . 
Ohio .... 
Iowa .... 
Pennsylvania . 
New Jersey 
Maine . . . 
Indiana . . . 
Michigan . . 
Massachusetts . 
Wisconsin . . 
All others . . 


23,739 
19,976 

18,387 

17,298 

12,568 

11,764 

10,442 

8,693 

7,977 

5,726 

4,942 

3,789 

32,923 


$942,023 
558,746 
386,277 
528,162 
219,220 
507,736 
557,708 
272,614 
188,054 
147,762 
355,953 
83,502 

1,208,662 


$39.35 
27.98 
21.00 
30.53 
17.44 
43.16 
53.41 
31.36 
23.57 
25.80 
72.23 
22.04 
36.80 


15,694 
44,983 
30,898 
28,231 
49,548 
3,941 

10,817 

11,075 

4,153 

7,456 
21,594 


1.1 

2.1 
1.9 
1.8 
1.9 

1.8 

1.9 
1.4 
0.6 

1.7 


United States . 


178,224 


5,936,419 


33.31 


228,390 


1.8 



259 



260 



CORN CROPS 



ing centers. In the eastern states the crop of Maine, 

Maryland, and western New York is largely grown for 

canneries. From 
Ohio westward 
sweet corn is grown 
principally for the 
canneries. The 
foregoing table 
shows the acreage 
and value for lead- 
ing states in 1909; 
also the acreage 
and yield to the 
acre for 1918, as 
published by the 
Bureau of Statis- 
tics. The latter 
data, however, is 
not total acreage 
but only acreage 
contracted for by 
canners. 

187. The value 
to the acre shows 
a wide variation. 
This is no doubt 
partly due to va- 
riation in yield se- 
cured in the states 
in the census year. 
Localized crops 

usually fluctuate in yield, much more than staple crops. 

The high value in certain states, as Massachusetts, New 




Fig. 92. 



An ear of green corn, at proper 
stage for table use. 



SWEET COBN OR SUGAR CORN 



261 




262 



COBN CROPS 



Jersey, and Pennsylvania, is due to the crop being grown 
in those states largely as a truck or market-garden crop, 
and sold as green corn, for immediate consumption. 
When the corn is sold to canneries, both the yield to the 
acre and price a ton is much* lower. 

188. Sweet corn for canning. — There is no available 
data in the last census on the exact acreage of corn for 
canning in each state. The previous table gives the num- 
ber of acres of sweet corn for canning in the leading states 
in 1918. These states, in ranking order, are Iowa, Illi- 
nois, Maryland, Ohio, and New York. 

Among canning crops, tomatoes rank first, sweet corn 
second, and peas third. The following data gives the 
number of cases (No. 2 cans) of the three principal crops 
for two years. 

Area Contracted For and Number of Cases Canned op 
Tomatoes, Sweet Corn, and Peas 



Crop 


Acreage Contracted 


Cases op Canned Goods 


1917 


1918 


1917 


1918 


Tomatoes . . 
Sweet Corn . . 
Peas .... 


246,010 
203,055 
114,047 


258,943 
228,390 
107,548 


15,076,074 

10,802,952 

9,829,153 


15,882,372 
11,721,860 
10,898,222 



189. Historical development. — While sweet com was 
mentioned previous to the year 1800, it does not appear 
to have been used much as a garden crop previous to 1825, 
which is about the date when it was first offered by the 
seed trade. Sweet corn seems to have come into general 
use as a garden crop by the late fifties. Home drying 
for family use was extensively practised, and later com- 
mercial drying was developed. With the development of 
commercial canning, 1880-90, sweet corn became an 
important canning crop. 



SWEET CORN OB SUGAR CORN 263 

Sweet corn culture, both as a market-garden crop and 
for commercial canning, developed first in the northeastern 
states. With the development of commercial canning, 
the crop moved westward into the corn-belt, largely on 
account of cheaper production. At present about 60 
per cent of the acreage is grown from Ohio westward. 

South of the Ohio River sweet corn has never developed 
as a commercial crop. This is probably due in part at 
least to attacks of the ear-worm. While the ear-worm 
is often injurious in the North, it is much more common 
and destructive in the South. 

190. Quality in sweet corn. — Quality is largely de- 
termined by (1) sugar-content and (2) tenderness. Sugar- 
content is usually highest just as the ear has reached full 
development, often described as the " dough " stage, but 
before the grains have hardened in a noticeable degree. 
The sugar-content decreases rapidly after the ear is 
broken from the stalk. The change is noticeable in a few 
hours, and after twenty-four hours the characteristic 
sweet taste has largely disappeared. This is the reason 
why it is seldom possible to buy good sweet corn on the 
market. For the best quality, sweet corn should be 
cooked within an hour after picking. In commercial 
canneries it is highly important to move the corn from 
field to factory in the shortest possible time. 

Tenderness relates to the toughening of the outer skin 
as the corn matures. The rate of ripening varies greatly 
with climatic conditions. In the western states, corn 
matures at a very rapid rate, due probably to the high 
temperatures and dry air. After reaching the prime stage, 
the corn will often be noticeably tough in twenty-four 
to forty-eight hours. By contrast, in the northeastern 
states, where the ripening process is slow, corn will usually 



264 CORN CROPS 

remain in prime condition for several days. This is 
probably the reason why canners have often claimed that 
the eastern corn produced a better canned product than 
western corn. Maine has long been noted for the quality 
of canned com. 

A careful comparative study was made some years ago 
by the United States Bureau of Chemistry. The results 
showed practically no difference in sugar-content, or in 
other measurable ways, between sweet corn in different 
sections East and West. It is undoubtedly more difficult 
to secure the crop in prime condition under western cli- 
rdatic conditions. 

VARIETIES AND TYPES 

191. Sweet corn may be divided into about the same 
general classes and types as field corn. The height of 
the stalk varies from three to ten feet and the number of 
rows on the ear from eight to twenty. Practically all 
common colors are found. The time from planting to 
maturity varies from 65 to 110 days. 

192. As mentioned before (page 23) sweet corn is any 
one of the starch corns (flint, dent, or flour corn) that has 
lost its faculty of coverting sugars into starches ; hence, 
a large part of its carbohydrate material remains in the 
form of sugar, although some starch may be developed. 

Sweet corn culture is most extensive in the vicinity of 
large cities, where it is grown as a market-garden and 
truck crop, and in regions where it is grown as a can- 
ning crop. 

193. Varieties. — The varieties of sweet corn are some- 
times classified as (1) canning, (2) truck or market- 
garden, and (3) home-garden varieties. No clear dis- 
tinction can be made, except in relative earliness. 



SWEET CORN- OR SUGAR CORN 265 

Canners use large late varieties very largely, Stowell 
Evergreen, and similar types, being most popular. 

Truck-growers use medium and late varieties mostly. 
Stowell Evergreen and Country Gentlemen are the 
leaders. The market-gardener generally grows early, 
medium and late ; although he is coming to select one or 
two good varieties for his market, and to depend on 
planting every two weeks, to have a succession throughout 
the season, rather than to plant several varieties. 

Home gardeners usually desire at least one very early 
variety. For the remainder of the season it is recom- 
mended to select one good medium variety and plant 
in succession every two weeks. A number of varieties 
is sometimes preferred as a matter of personal taste, rather 
than for practical considerations. 

Following are standard and well-known varieties : 

Early Medium Late 

Golden Bantam Semours Sweet Country Gentlemen 
White Cob Cory Orange Stowell Evergreen 

Adams Early Crosby Mammoth Late 

Black Mexican 

Local strains of these varieties vary, due to different 
standards of selection or effect of environment where the 
seed is grown. 

SEED PRODUCTION 

About 85 per cent of the sweet corn seed is grown in 
states from Ohio westward, in scattered sections through- 
out the corn-belt. About 60 per cent of the acreage is in 
the three states of Ohio, Iowa, and Nebraska. From the 
seed survey made in 1918, the following table was pubHshed 
showing the acreage and production of sweet corn seed. 
(Crop Reporter, November, 1918.) 



266 



COBN CROPS 



Acreage (1918) and Usual Production of Sweet Corn Seed 
IN THE United States 



State 


Number of 

Acres Planted 

1918 


Reported Yieli? 
Usually Ob- 
tained 


Date of 

Harvesting 

Is Generally 


New Hampshir 
Massachusetts 
Connecticut 
New York . 

Michigan . 
Illinois . . 
Indiana . . 
Ohio . . . 
South Dakota 
Minnesota . 

Nebraska . 
Iowa . . . 
Colorado . 
Oregon . 
Idaho . . 
California . 


e . 




5 

72 

1,485 

662 

1,841 
100 
298 

3,168 
109 
267 

3,122 

2,304 

84 

25 

20 

304 


1,000 
1,500 
1,650 
1,350 

1,000 
1,300 
1,050 
1,050 
1,400 
1,050 

1,450 
1,450 
1,650 
1,000 
1,500 
1,000 


Oct. 15 
Oct. 10 
Nov. 1 
Oct. 25 

Oct. 15 
Oct. 20 


Nov. 1 
Oct. 20 
Sept. 10 

Nov. 1 
Oct. 15 
Oct. 10 
Oct. 1 
Oct. 10 
Dec. 15 


United States 






13,934 


1,325 





194. Breeding and selecting sweet corn offers an in- 
teresting and useful field of work both for the small gar- 
dener and large grower. Many of the large canning com- 
panies and commercial growers select and produce their 
own seed. This often enables them to secure a type 
especially suited to their own needs. 

As explained (page 105), the sweet corn grain type 
segregates out in hybrids. The sweet corn grain is reces- 
sive. This makes it possible to cross sweet corn with any 
starchy corn and by selecting pure sweet corn grains, 
have pure sweet corns, that breed true. 



SWEET CORN OR SUGAR CORN 



267 



SELECTING AND CURING SWEET CORN 

195. Methods of selection and improvement with 
field corn have been fully discussed (pp. 85-121). The 
methods may be applied to the improvement of sweet 
corn. 

The type of ear to be selected will vary with require- 
ments. In the canning industry, rather large, straight, 
and uniform ears are desirable, as they can be handled 



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Fig. 94. — Handy rack for drying seed corn. 



better by the machinery. For home-garden and market- 
gardens, medium or even small ears are satisfactory and 
often desirable. There is a Hmited demand for very 
early sweet corn. Extreme earliness, however, usually 
means a small ear and shallow kernel. 

In selecting seed ears, it is desirable to have a clear, 



268 CORN CROPS 

translucent kernel, with no sign of starchiness. This is 
believed to indicate a higher sugar-content, though exact 
content of sugar cannot be determined without a chemical 
analysis. 

196. Drying sweet corn seed. — One of the most 
important factors in the sweet corn industry is the proper 
curing of the seed ears. Sweet corn molds and ferments 
more readily than field corn. Sweet corn cut and shocked 
up like field corn will often sour before it dries, while the 
latter will cure out in a satisfactory manner. Sweet corn 
ears on the standing stalk will often mold and lose their 
germinating quality if the weather is warm and humid. 
For this reason much of the sweet corn seed is now raised 
in the western end of the corn-belt, where fall weather is 
likely to be dry and clear. 

In New York and Connecticut, where commercial sweet 
corn seed is grown, it is a common custom to top the fields, 
when the ears have reached maturity. The top is cut 
just above the ears, leaving the ears exposed to air and 
sunshine. Sometimes the husks are also pulled back to 
hasten drying. When the ears have thoroughly ripened 
and dried on the stalk, the corn is gathered and placed 
in a well-ventilated building, either in slatted crates, or 
on slatted floors, spread out to facilitate drying. Heat 
is sometimes used to hasten the drying.^ 

GROWING SWEET CORN FOR CANNING 

197. Canning corn is grown under contract with the firm 
in many corn-growing regions. The canning company 
sends out a contract similar to the following : — 

1 For some further information on handling sweet corn seed see : 
Tracy, W. W., The Production of Vegetable Seeds, Sweet Corn, etc. 
B. P. I. Bui. No. 184. 1910. 



SWEET CORN OB SUGAR CORN 269 

Sweet corn agreement 

(Place), (Date) 

This agreement made with the Canning Com- 
pany, by which I hereby agree to plant and raise for said 
Company acres of sweet corn, the same to be de- 
livered at factory from time to time as required by said 
Company, in proper condition for canning during the 
season of 191- ; for which said Company agrees to pay 
seven dollars per ton, said Company to furnish me at their 
factory seed corn at the proper time for planting. For 
said seed corn I agree to pay said Company two dollars 
per bushel on or before the first day of October, 191-, or 
from the proceeds of corn delivered on this contract. I 
further agree (1st) to plant said corn in three different 

plantings, first planting, acres, to be planted early 

in May ; second and third plantings, acres, to be 

planted the last of M3,y or the first week in June, or after 
each preceding planting is well up. (2d) Not to let any 
corn become heated or damaged by remaining in bulk 
too long, and to deliver said corn the day it is picked. 
(3d) To make a short snap close to the ear. (4th) It 
is further agreed that the corn covered in this contract 
shall not be paid for till October first, 191-. (5th) That 
corn must not be planted near field corn unless it be white 
field corn, as mixed yellow corn is unfit for canning. In 
case of destruction of the cannery by the elements, said 
Company not to be held liable for damages on this contract. 

(Signed) (The Company) 
(Signed) (The Farmer) 

198. Rotation. — It is often to the advantage of the 
growers to plant their cannery corn crop in rotation with 
other crops. It is desirable that the corn be planted 



270 CORN CROPS 

following a sod, especially if on this sod from eight to ten 
tons of stable manure are applied and plowed under. If 
choice of soil is obtainable, the piece of ground that will give 
the most satisfactory results is a gravelly or a sandy loam, 
especially if there is some chance of having humus, such 
as sod or manure. The corn is generally planted with a 
machine, either one- or two-row corn planter ; and at the 
same time, some growers apply from three to five hundred 
pounds of a 3-8-5 fertilizer formula, or if the manure is 
deficient, up to 1000 to 1200 pounds of fertihzer of the 
same formula. In some cases, growers raising sweet 
com place not only the above amount of manure on their 
ground, but sometimes more, and add the larger amount 
of fertilizer, as well. 

199. Distance between the rows and hills will vary with 
the size of the corn and machinery available for planting 
and cultivation. The smaller varieties are planted closer 
than large ones. 

In the West, where sweet corn is grown largely as a can- 
ning crop, the same tools are used as in the culture of field 
corn. The methods of planting and cultivation are similar. 

In the eastern states, the planting is done with one- 
horse drills, or hand planted. The methods of culture 
follow more closely the practices of the truck-farmers 
and market-gardeners. The land is often heavily manured 
or fertilized, and the planting much closer than in the 
West. Hills 36 inches square or 30 inches by 36 inches 
are common practice. Under the more intensive methods, 
the corn is often planted 6 or 8 grains to the hill, and later 
thinned out. A little fertilizer or compost is often put 
in each hill to hasten early growth. Both hill and drill 
planting are practiced, the custom varying with localities 
and the tools available. 



SWEET CORN OB SUGAR CORN 271 

200. Tillage. — The weeder is used soon after the seed 
is planted, or a fine-tooth harrow. When the com has 
broken ground, the weeding is generally discontinued, 
and a fine-tooth cultivator used. This may be a one-row 
or a two-row cultivator. The general plan at first in culti- 
vation is to till rather deeply, especially in the middle of 
the row between the plants, later tilling more shallow. 
It may be an advantage to go through with a hand hoe. 
When it is seen that the horse and machine in cultivating 
are injuring the corn, this work is discontinued, and the 
corn is allowed to grow without further attention. 

When ready for market, the factories generally send 
a man to the field to instruct the farmer just when to 
bring the corn to the factory. In the different sections, 
there is some difference of opinion as to when the com 
should be harvested for the factory and just how. In 
general, the corn should be delivered to the factory as soon 
as possible after breaking from the stalk. There are some 
companies that desire the corn broken in the morning and 
carted immediately to their factories. As stated in a 
number of reports received from canners, they did not 
desire the growers to pick the corn in the late afternoon 
and allow this to stand in the wagons over night, owing 
to heating of the corn. 

In harvesting, the ear is broken from the plant so that 
there is very little or no stub left on the base, and the 
unnecessary husks as well are taken off. However, no 
extra attention or care is given at this period. The corn 
may be gathered in baskets or in boxes, and immediately 
emptied in a wagon. When the wagon is full, it is taken 
to the factory and there weighed, if sold at so much a ton 
green weight. 

201. The market-garden crop is generally grown on 



272 CORN CHOPS 

high-priced land near the centers of population. The 
soil is generally in the best condition and of the typical 
market-garden type, a sandy loam well supphed with 
humus, and improved each year by apphcations of ma- 
nure, sometimes as high as 40 tons to the acre. Besides 
the heavy applications of manure, some market-gardeners 
use large quantities of commercial fertilizer. The general 
idea among them is that in order to get an early crop 
of sweet corn, which is the one that brings the highest 
money, they should have food for the plant quickly 
available. 

202. From six to eight kernels, in some cases more, are 
planted in each hill. For the early varieties, the hills may 
be as close as one foot. From fifteen to eighteen inches is 
more nearly the average distance between hills in the row. 
The distance between rows varies from twenty-four to 
thirty inches. The cleanest culture is given, and irriga- 
tion is practiced in some cases. 

Market-gardeners, by their intensive methods of plant- 
ing, are able to place corn on the market from ten days 
to two weeks earlier than men living a little farther back 
from the centers of population, and practicing less inten- 
sive methods. In cultivating the corn, especially with the 
hoe, suckering is generally practiced. 

Cultivation is continued thoroughly and as long as 
possible, the horse being muzzled when it is found that 
injury results. If the com is not growing to suit, slight 
applications of fertilizer, especially nitrate of soda 100 to 
150 pounds per acre, are made. 

In planting the early and main season and late varie- 
ties, some planters practice sowing the seed at the same 
time, and allowing the difference in the period of maturity 
to bring the crop in at the proper time. Other growers 



SWEET CORN OB SUGAR CORN 21 S 

prefer to plant their corn at intervals of ten days to two 
weeks. This latter seems to be the most practicable 
method. 

203. Marketing. — As soon as the ear is at the right 
stage for harvesting it is broken from the plant and placed 
in baskets or boxes, immediately taken to the shed, and 
there repacked: In, the eastern markets, especially in New 
England, the corn is packed in boxes, a certain definite 
number of ears in each box. For New York and Phila- 
delphia and through the North and West, ears are sold 
by the hundred in sacks or hampers. This is less satis- 
factory. It is not a pleasing pack or one that attracts 
attention. The bushel box is more practical, more up to 
date, and the corn carries better. In the sack the corn 
has been known to heat because too much was placed 
together. 

204. The first corn coming to the market sells for thirty 
to forty and in some cases fifty cents a dozen. It then 
steadily declines until it reaches eight and even six cents 
a dozen. If a man has a retail route and has corn through- 
out the season, he usually maintains a high average price. 
Some men never sell for less than fifteen cents throughout 
the season from their retail wagons. 

205. The bulk of the main crop and the late crop are 
grown a little farther back from cities on less expensive 
land, and under less intensive methods. The rows and 
hills are generally a little farther apart, three feet to forty- 
two inches between rows, and from thirty to thirty-six 
inches between hills in the row. Fertilizer up to a thou- 
sand or twelve hundred pounds is applied with the corn. 
The corn is commonly planted on sod ground, this being 
usually spring plowed. Clean culture is practiced in the 
early part of the season. The corn is generally harvested 



274 COBN CROPS 

the same as for the market-gardening. When grading and 
packing is necessary, the ears should be of miiform size 
and about the same degree of maturity. Better prices 
can be thus secured. The com is usually shipped to 
commission houses, to wholesale stores, to clubs and hotels. 
Gross returns of $100 an acre will make a crop of corn 
profitable. As high as $350 the acre has been received 
from sweet corn. 

FOKCING SWEET CORN 

206. Forcing sweet corn for early market or in private 
gardens has been practiced to a limited extent. Three 
methods may be mentioned : (1) Growing in a greenhouse, 
(2) starting in hotbeds, and (3) starting in paper pots to be 
transplanted later. 

Growing in greenhouses does not appear to be justified 
as a commercial practice. When hotbeds or coldframes 
have been used for some early crop, they are sometimes 
replanted with early sweet corn. The corn is allowed to 
grow under the glass until all danger of frost is past and 
then grown in the beds to maturity. 

The corn is also sometimes started in paper pots. Two 
or three seeds are planted to each pot and later when 
danger of frost is past transplanted to the garden. The 
corn should not be allowed to become too large, as there is 
not much room for root development, and there is danger 
of the plants being permanently stunted. About four 
to six inches is the correct height when transplanted. 

SWEET CORN IN THE HOME GARDEN 

207. In the home garden the aim should be to have a 
Hberal and constant supply of sweet corn. The variety 
should correspond with the personal taste of the individual 



SWEET CORN OB SUGAR CORN 275 

gardener or consumer. It is doubtful whether the extra 
early corns will answer the demands of the individual 
home gardeners, as they lack somewhat in quality. 

The home gardener does not have a great choice of soil 
for the growing of sweet corn. The garden may be heavy 
clay or light loam. In either case the principal treatment 
should be liberal applications of stable manure. Some per- 
sons apply a httle commercial fertilizer, but this is the ex- 
ception rather than the rule. No fertilizer is needed if the 
garden has plenty of manure. Sweet corn in the home 
garden may be grown under the methods described for 
commercial growing. Transplanting corn from hotbeds 
is a feasible method for the home garden, especially for 
early corn. Inter-cropping of the corn, in the earliest 
stages when planted from seed, would be practical. Such 
crops as radishes, spinach, lettuce, and even beans can be 
grown in the home garden, utilizing apparently waste 
space, which later is necessary for the full development 
of the corn. 



PART II 
SORGHUMS 



CHAPTER XXIII 
THE SORGHUM PLANT 

Sorghum (Andropogon Sorghum var. vulgaris, Hackel, 
A. Sorghum, Brot., Sorghum vulgare, Pers.) is generally 
conceded to have been originally derived from the well- 
known wild species, Androj)ogon halepensis, Brot. 

The wild species is found abundantly in all tropical 
and subtropical parts of the Old World and has been in- 
troduced into the Western Hemisphere, where it is now 
well distributed in both North and South America between 
the parallels of latitude thirty degrees north and south of 
the equator. 

209. Andropogon halepensis is generally known in the 
United States as Johnson-grass. Johnson-grass is a coarse- 
growing perennial, with strong underground rootstocks by 
means of which it spreads rapidly and is very persistent, 
being regarded generally as a bad weed. 

Sorghum differs from the wild form in that it is larger- 
growing, that it produces more seed, that certain forms 
have abundant sweet juice, and that no form is perennial 
or has persistent rootstocks. However, there are forms of 
Andropogon halepensis that are annual and without the 
persistent rootstocks, an example being the variety known 
as " Soudan grass." The wild form is somewhat vari- 
able, having certain types paralleling in their variations 
the cultivated forms. 

279 



280 



GOBN CROPS 



GEOGKAPHICAL ORIGIN 

210. Hackel ^ states that the cultivated forms had their 
origin in Africa, but BalP beheves that they also had 
an independent origin in India as well. 

The early history of sorghum culture is unknown, but 




Fig. 95. — Plant of sorghum. (After Fuchs, 1542.) 

1 Hackel, Edward. The True Grasses, p. 59. 

2 Ball, Carleton R. U. S.' Dept. Agr., Bur. Plant Indus., Bui. 
175, pp. 9-10. 



THE SOBGHUM PLANT 281 

there is good evidence that it was an important crop in 
both Africa and South Asia hundreds of years before the 
Christian Era. A reference to millet in the Bible 
(600 B.C.) probably refers to sorghum. (Ezek. x. 4. The 
word millet is translated " dochan " in the original 
Hebrew text, a word still in use in Arabic for various 
forms of sorghum.) Sorghum is well adapted to meet the 
needs of a primitive agriculture. The seeds provide 
human food, while the plant furnishes abundant fodder for 
animals. Under favorable conditions the plant will run 
wild to some extent, and is better able to care for itself 
than any other of our important cultivated plants. 

Sorghum is at present the most important cereal food 
of the native people of Africa, and is a very important 
crop through the southern half of Asia. There are no 
statistics of the world's production of sorghum. The 
United States crop is estimated at about 3,000,000 acres 
and that of India at 25,000,000. The crop of Africa and of 
Asia Minor should approximate that of India. 

BOTANICAL CLASSIFICATION 

Order — Graminece. 

Tribe — Andropogonece. 

Genus — Andropogon. 

Species — A. Sorghum var. vulgare. 

211. Ball ^ has suggested the following classification as a 
key to the principal groups of sorghum : — 
I. Pith juicy. 

A. Juice abundant and very sweet. 

1. Internodes elongated ; sheaths scarcely overlapping; 
leaves 12-15 (except in Amber varieties) ; spike- 
lets elliptic-oval to obovate, 2.5-3.5 mm. wide; 
seeds reddish brown. I. Sorgo 

1 Ball, Cableton R. U. S. Dept. Agr., Bur. Plant Indus., Bui. 175, p. 8. 



282 CORN CROPS 

B. Juice scanty, slightly sweet to subacid. 

1. Internodes short; sheaths strongly overlapping; 

leaves 12-15 ; peduncles erect ; panicles cylin- 
drical ; spikelets obovate, 3-4 mm. wide ; 
lemmas awnless. II. Kafir. 

2. Internodes medium ; sheaths scarcely overlapping ; 

leaves 8-11 ; peduncles mostly inclined, often 
recurved ; panicles ovate ; spikelets broadly 
obovate, 4.5-6 mm. wide; lemmas awned. 

VII. Milo. 
II. Pith dry. 

A. Panicle lax, 2.5-7 dm. long; peduncles erect; spikelets 

elliptic-oval or obovate, 2.5-3.5 mm. wide ; 
lemmas awned. 

1. Panicle 4-7 dm. long; rachis less than one-fifth as 

long as the panicle. 
a. Panicle umbelliform, the branches greatly elon- 
gated, the tips drooping ; seeds reddish, in- 
cluded. III. Broom-corn. 

2. Panicle 2.5-4 dm. long; rachis more than two- 

thirds as long as the panicle. 
a. Panicle conical, the branches strongly drooping; 

glumes at maturity spreading and involute ; seeds 

white, brown, or somewhat buff. IV. Shallu. 
h. Panicle oval or obovate, the branches spreading ; 

glumes at maturity appressed, not involute ; 

seeds white, brown, or reddish. V. KowUang. 

B, Panicle compact, 1-2.5 dm. long; peduncles erect or 

recurved ; rhachis more than two-thirds as long 
as the panicle. 

1. Spikelets elKptic-oval or obovate, 2.5-3.5 mm. wide ; 

lemmas awned. V. Kowhang. 

2. Spikelets broadly obovate, 4.5-6 mm. wide. 

a. Glumes gray or greenish, not wrinkled; densely 

pubescent ; lemmas awned or awnless ; seeds 
strongly flattened. VI. Durra. 

b. Glumes deep brown or black, transversely 

wrinkled ; thinly pubescent ; lemmas awned ; 
seeds slightly flattened. VII. Milo. 



THE SOBGHUM PLANT 283 

212. Technical description. — The plant varies in height 
from about 4 feet (dwarf Milo) to 12 or 15 feet high in 
some of the tropical forms. 

Panicle, or " head," varies in shape from the small, 
compact " sumac " type, in Avhich the rachis is almost 
as long as the panicle, through the looser and more branch- 
ing forms of the Collier type, in which the rachis is about 
one-half that of the panicle, to the broom-corn type, in 
which the rachis is onlj^ one-fifth the length of the branches. 

Seeds. — The shape of seed varies, from round in the 
Kafir, Kowliang, and Shallu, to somewhat pear-shaped in 
certain of the sweet sorghums, somewhat flattened in Milo, 
and decidedly flat in the Durras. The seed coat of all 
dark-colored varieties has a decidedly astringent taste, 
due to the presence of tannin. The amount of tannin 
seems to vary with the color, being greatest in the black- 
seeded and dark red varieties, very little in yellow seeds, 
and there being none in white seeds. The astringency 
apparently has no ill effect except as it affects flavor, the 
dark-seeded grain not being so desirable for stock food on 
this account. 

Stems. — Stems vary not only in height (from 4 to 15 
feet), but also in relative thickness. The Amber variety 
is slender, with stems less than 1 inch in diameter, while in 
the Gooseneck variety the stems are 1 to 2 inches thick. 
In slender-stemmed varieties the nodes are usually long, 
about 12 inches; while in the stouter-stemmed varieties 
the tendency is toward short nodes, as in the Sumac, 
the average length being 8 or 9 inches. 

Juices. — Stems are designated as juicy or dry. The 
actual water content of the green stems does not differ so 
much in the two cases, the green stems being 80 to 90 per 
cent water. In the juicy-stemmed varieties the juice is 



284 COBN CROPS 

easily extracted by crushing and pressing. An ordinary 
roller cane press will extract 50 to 60 per cent of the juice. 

Not all juicy sorghums are sweet, but practically all 
the very juicy varieties are. The sugar content of the 
juice in sweet sorghums varies from 10 to 18 per cent. 

Leaves. — The leaves of the sorghums are strong and 
are especially well adapted to withstand the rather dry 
and often hot winds that prevail in semiarid regions. 
In periods of protracted drought the leaves assume a 
rather erect position, rolhng together to a considerable 
degree in a way that appears to protect against exces- 
sive evaporation. All the very drought-resistant forms, 
as the Milo and Durra types, are rather scanty-leaved; 
the leaves being about eight to ten in number, rather 
broad and short, and rather coarse in texture. 

Tillers. — All varieties of sorghum seem to produce 
tillers abundantly. These appear at the lower joints of 
the stem. The buds that develop into tillers may re- 
main more or less dormant when conditions for growth are 
unfavorable, ready, however, to develop at the first favor- 
able opportunity. Fertile soil and thin planting favor 
their development. Certain varieties, however, seem to 
produce two or more tillers normally, the tillers starting 
almost as soon as the main stem, and it is only under the 
very thickest planting that they are suppressed. 

It sometimes occurs, when the first part of the season is 
dry and unfavorable, that the main stem may become 
stunted ; if late rains come, the tillers will often grow much 
taller than the main stalk. The tillers are later in matur- 
ing and are considered undesirable when the crop is 
grown for grain or sirup ; but they are usually desirable 
when the crop is grown for forage, as they no doubt in- 
crease the yield of fodder. 



THE SOBGHUM PLANT 285 

When sorghum plants are cut off, tillers usually spring 
up at once. In the South two crops, and even three 
crops, may be cut from the same roots. In regions of 
very mild winters the roots of certain varieties will live 
over, giving a crop the second year. 

Branches. — Branches come from latent buds on the 
upper part of the stem as tillers do from the lower nodes. 
The same conditions that favor tillering favor the 
development of branches. The first branch appears 
from the topmost node, the second from the next, and so 
on down, in order ; under very favorable conditions and 
thin planting, four or five branches may develop. Each 
branch bears a small head, similar to the main head but 
later in maturing. 

Branches are considered undesirable, and the usual 
plan is to plant the sorghum thick enough so that there 
will be neither tillering nor branching. 

Roots. — The Kansas station made a study of Kafir 
corn and sweet sorghum roots in comparison with corn and 
other field crops. The roots of Kafir corn were found to be 
finer and more fibrous than corn roots under the same con- 
ditions. A few of the longer Kafir roots penetrated to a 
depth of 3 feet, but most of them were confined to the 
upper 18 inches, filling the soil to this depth with a fine 
network of roots; while corn under the same conditions 
fully occupied the upper 30 inches with roots (see Fig. 12, 
page 27), sending its deepest roots about 4 feet. The 
sweet sorghum roots were somewhat intermediate in char- 
acter, but resembled the Kafir more than the corn roots.' 

The distribution of roots indicates that the sorghums 
draw their nutrients from the surface soil much more 
than corn. 

1 Kans. Agr. Exp. Sta., Bui. 127, pp. 207-208. 1904. 



286 CORN CROPS 

PHYSIOLOGY OP THE SOKGHUMS 

213. In general, the physiology and nutrition of sor- 
ghum are similar to those of corn, which has been set forth 
(page 38). The most interesting physical phenomenon of 
sorghum from an economic standpoint is its general re- 
sistance to drought and to the climatic conditions that 
prevail in dry climates. 

Drought resistance. — The drought resistance of sor- 
ghum is well established. Its ability to yield in a dry 
climate is apparently not due to a deep root system or to 
any other adaptation of the root system so far reported. 
Neither does it seem to be due to a low water requirement, 
as the few tests made on this point indicate that quite as 
much is required per pound of dry weight as for Indian 
corn or for other crops not particularly adapted to dry 
conditions. 

The success of sorghum under semiarid conditions 
seems to depend on two qualities, not found developed 
to so great a degree in other crops : (1) The high resist- 
ance of leaves to injury from hot, dry weather. The non- 
saccharine groups, especially, will withstand dry and hot 
climatic conditions that would wither most vegetation be- 
yond recovery. (2) The plants have the faculty of becom- 
ing almost dormant, so far as growth is concerned, for 
long periods during severe drought. During such periods 
the leaves roll and tend to assume an upright position. 
This, no doubt, reduces evaporation from the leaves and 
affords protection to the younger leaves and the seed 
head. The plant may remain in this condition, apparently 
without growth, for several weeks, far beyond the endur- 
ance of most cultivated plants. With the coming of rain, 
growth will usually be renewed with vigor. If the main 



THE SORGHUM PLANT 287 

stalk has been much stunted, tillers will often grow up at 
once and become taller than the main stalk. While 
tillers do not usually produce a good seed crop, they are 
satisfactory as forage. 

REPRODUCTION 

214. The sorghums are all " perfect-flowered " — the 
pollen and ovary being in the same flower, instead of in 
separate flowers as in corn. This is the principal botanical 
distinction between the tribe Maydeos, to which corn 
belongs, and the tribe Andropogonece, to which sorghum 
belongs. 

FERTILIZATION 

215. All sorghums are adapted to both self-fertilization 
and wind fertilization. Apparently, self-fertilization is 
normal in the sorghums, and is in no way injurious as it is 
in corn (page 107). In developing pure strains of sorghum 
it has been found practicable to cover the heads with 
bags before blooming, thus securing complete self-fertili- 
zation. 

NATURAL CROSSING 

216. Under normal field conditions more or less crossing 
takes place. Regarding this point Ball^ makes the fol- 
lowing statement : " Just to what extent cross-fertiliza- 
tion takes place under normal field conditions, it is, of 
course, impossible to say. However, in the case of ad- 
jacent rows of different varieties, flowering on approxi- 
mately the same dates, as high as 50 per cent of the seed 
produced on the leeward row has been found to be cross- 
fertilized. It is probable that in a fairly uniform field 
of any given variety a similar percentage of natural 

1 Ball, Carleton R. American Breeders' Association, Vol. YI, p. 193. 



288 COBN CROPS 

crossing takes place. Many writers have stated that 
such cross-polhnation occurs also at very long distances, 
but this seems to be less conclusively proved. Probably 
a distance of 8 to 10 rods to leeward is the maximum at 
which appreciable hybridization occurs." Ball also states 
that the pollen is mostly shed during the early morning 
hours, when the winds are usually at lower velocities 
than later in the day. 

Crossing of types. — All the different types of sorghum, 
as sweet sorghums, non-saccharine types, and broom-corns, 
cross readily. (See Fig. 115.) Broom-corn growers must 
exercise some care in keeping their seed stocks pure, in 
regions where other varieties of sorghum are grown. 

CLIMATE AND SOILS 

217. 'The entire botanical genus (Andropogon), made up 
of hundreds of species, is found growing principally in 
wide-open plains regions. Hackel ^ states, " the species 
prefer dry places, especially savannas." 

Climatic requirements 

Temperature and sunshine. — Sorghum, like corn, is a 
plant of tropical origin, varieties of which have been 
adapted to temperate climates. Like corn, it requires 
abundant sunshine and warm weather, being very sensitive 
to cool nights. At high elevations where nights are gen- 
erally cool, sorghum seldom does well even when the days 
are warm and sunshiny. 

Humidity and rainfall. — While both corn and sorghum 
require sunshine and warmth, they apparently differ 
somewhat as to humidity, corn preferring regions of high 

1 Hackel, Edwakd. The True Grasses, p. 57. 



THE SOBGHUM PLANT 289 

humidity such as prevail in the Mississippi valley, and 
sorghum preferring regions of dry air such as prevail in 
the Great Plains region of the upper Missouri River 
valley and southward. 

The above general difference may be due in part to 
selection of varieties. Sorghum being of tropical origin 
and widely distributed, certain varieties flourish in very 
humid regions of Africa. Certain varieties of the sweet 
sorghums grow well in the Carol inas and Gulf States, 
where both rainfall and humidity are high. 

While certain sorghums do well under humid conditions, 
the ability of all sorghums to remain more or less dormant 
during periods of drought, and to renew growth with the 
return of rain, has qualified the crop for adaptation to dry 
climates. For centuries sorghums have been grown and 
adapted to dry conditions in the Old World as they are 
being further adapted in the United States. The result 
is that the principal varieties of sorghum under cultivation 
prefer a drier and warmer climate than is required by the 
corn crop, although no doubt varieties of sorghum could 
be found equally adapted to humid regions. The above 
conclusion applies with more truth to the grain sorghums 
(Kafirs and Durras) than to the sweet sorghums or broom- 
corns. 

Soil requirements 

218. The sorghums are adapted to a wide range of soils, 
but they prefer a medium- weight loam to very light or very 
heavy soils. The grain sorghums are apparently more 
sensitive in this respect than the sweet sorghums. Sor- 
ghums for forage are often grown on poor land, not only 
because they produce more forage than any other crop 
under such conditions, but also because the stems are 
finer than when grown on heavy land. 
u 



290 CORN CROPS 

219. Effect on the land. — The sweet sorghums sown 
thickly have the reputation of being " hard on the land." 
Grain sorghums planted thin seem to have the same effect 
also, in lesser degree. All millets have the same reputation. 
No very satisfactory explanation for this has been ad- 
vanced. When the effect is noted it is most marked on the 
first crop following, and less marked afterward, usually 
completely disappearing in one or two years. The effect 
is most marked on small grain and less on intertilled 
crops. 

As the sorghum roots are rather concentrated in the 
upper layers of soil, it is possible that this soil is very much 
exhausted of available fertihty. There is some reason to 
believe that sorghums may exhaust available fertility to 
lower limits than do other crops. It is not known whether 
sorghums have a toxic effect on the soil. 

The injurious effect when noted is considered only 
temporary, and farmers in general do not consider it a 
serious drawback to sorgham culture. 

220. Alkali resistance. — Sorghum is often said to be 
alkali-resistant. It is not resistant in the same sense 
as are many native alkali plants, but at least it is one of 
the best of our cultivated plants to succeed on land rich 
in alkali. 

SORGHUM TYPES 

221. A common grouping, based principally on the 
economic use of the crop, is (a) Saccharine sorghums, (6) 
Non-saccharine sorghums, (c) Broom-corns. 

A. Saccharine sorghums. Those having an abundant sweet 
juice. Cultivated at one time principally for sirup manu- 
facture, but now principally as a forage plant. Commonly 
known as " sorghum.'! I. Sorgo. 



THE SORGHUM PLANT 291 

B. Non-saccharine sorghums. 

1. Pith contains a scant juice, which varies from slightly 

sweet in some varieties to subacid in others. Grown princi- 
pally for the grain, but also has forage value. II. Kafir. 

III. Milo. 

2. Pith dry. 

{a) Grown principally for the grain and forage. 

II. Kafir. 

VI. Durra. 

IV. Shallu. 

V. Kowliang. 

(&) Grown for the brush, no value as forage. 

VII. Broom-corn. 

The economic discussion of sorghums will follow the 
above grouping. 




292 



CHAPTER XXIV 

THE SACCHARINE SORGHUMS 

Sweet Sorghums 

222. This group of sorghums is usually designated as 
sweet sorghums, or ''sugar" sorghums. They are quite 
distinct from the non-saccharine, grain sorghums in having 
a juicy stem containing a high percentage of sugar and in 
producing a rather light seed crop. 

Early culture. — The sweet sorghums have never been 
cultivated extensively in the Old World, where the 
sorghums have been cultivated more for seed than for 
forage — the non-saccharine forms being more productive 
for the former purpose. The sweet sorghums seem to have 
been kept in cultivation principally for the sweet canes, 
which, however, were not manufactured but were peeled 
and the juice was expressed by chewing. Almost no sweet 
sorghum is raised in North Africa or in India ; it has been 
kept in cultivation in China and South Africa, however, 
though only in a small way. 

223. Introduction into the United States. — The first 
recorded introduction into the United States was from 
China in 1853, by way of France, and the plant was known 
at first as " Chinese Sorgo." This was a loose-panicled 
sorghum, from which have been derived most of our 
cultivated varieties of Amber sorghum. " Our Early 
Amber is said to have originated in 1859 as a sport in a 
field of Chinese sorgo growing in Indiana." ^ 

1 Ball, Cableton R. I.e., p. 25. 
293 



294 CORN CROPS 

A collection of sixteen varieties of sorghum brought 
from Natal, South Africa, to Europe in 1854 and from 
Europe to this country in 1857, included several sweet 
sorghums, from which have been derived our compact- 
headed types such as Orange, Sumac, and Gooseneck. 

Development of culture in the United States. — While 
sweet sorghum has remained a secondary crop in the Old 
World, it had a rather rapid development in the United 
States, owing to the belief that it would become a great 
sugar- and sirup-producing crop. In 1857 the United 
States Patent Office distributed 275 bushels in small lots 
to farmers ; The American Agriculturist distributed to its 
subscribers 1600 pounds in small packages, and the next 
year 34,500 pounds in the same way. At this time exten- 
sive experiments were being made with it in Europe for 
the manufacture of sugar, and later the United States 
Government ^ conducted an elaborate series of experiments 
for the same purpose. With the development of sugar 
beets at this time a better source of crystallized sugar was 
found, and the plan of using sorghum for this purpose was 
abandoned. 

First grown as a sirup crop. — However, sorghum was 
found to be a cheap source of home made sirup and it was 
more or less grown for this purpose in every rural com- 
munity. Local " sorghum mills " were very common dur- 
ing the eighties in the Central and Western States. Dur- 
ing the dry years in the early eighties, and again during 
the general drought of 1892-1894 in Nebraska, Kansas, 
and southward, sorghums of all kinds were found to with- 
stand drought, and its value as a forage crop was recognized. 

There are no available data on acreage of sweet sor- 
ghum, but the data on Kafir corn (page 304) indicate the 

1 See U. S. Dept. Agr., Bur. Chem., Buls. 26, 40, etc. 



THE SACCHARINE SORGHUMS 



295 




, CENSUS . 
Ifi THOUSANDS 



Fig. 97. — Production of sorghum sirup middle of last century. 




PROOUCTh 

CENSUS- 
iNTHOUS/INOS 



373 THommo 
S/IUOliS 



Fig. 98. — Production of sirup at close of century. 



296 COBN CROPS 

increase of sweet sorghum as the acreage of the two crops 
of late years is about equal. Beginning with 1890, the 
acreage has continued to increase up to the present 
time. 

224. How the crop is utilized. — In the Central States 
east of the Mississippi River, sweet sorghums have been 
cultivated principally since 1865 for "the manufacture of 
sirup. The extent of sirup manufacture for the census 
year is as follows : — 

Year Gallons 

1860 6,749,123 

1870 16,750,089 

1880 28,444,202 

1890 24,235,219 

1900 16,972,783 

1909 16,532,382 

The principal States in sirup manufacture for the last 
three decades have been Tennessee, Missouri, and Ken- 
tucky, but the industry has shown a rapid decrease in 
all these States. In only one State, North Carolina, has 
it shown a notable increase. Figures 97 and 98 show 
graphically the distribution at two periods. 

225. As a forage crop. — ■ West of the Missouri River 
and southward in the Great Plains region, the culture of 
sweet sorghum is principally as a forage crop. It is an 
important forage crop in the drier parts of Kansas, 
Oklahoma, Nebraska, ^ and Texas. The use of sweet 
sorghum as a forage crop has developed since 1880. 

226. Classification of sweet sorghums. — The following 
classification is adapted from Ball : — 

A. Peduncle and panicle erect. 

1. Panicle loose, open, branches spreading to horizontal 
or drooping ; rachis two-thirds as long to equaling 
the panicle. 



THE SACCHARINE SOBGHUMS 297 

Empty glumes black, hairy. I. Amber. 

Empty glumes black, smooth. II. Minn. Amber. 

Empty glumes red. III. Red Amber. 

Empty glumes light brown. IV. Honey. 

Rachis less than one-half the length of the panicle : — • 
Panicle light, drooping branches, seeds orange to red. 

V. Collier. 
Panicle heavy, seeds orange. VI. Planter's Friend. 
2. Panicle close, compact. 

Empty glumes equal to seeds, seed red. VII. Orange. 

Empty glumes half as long as the small seeds, seeds 

dark red. VIII. Sumac. 

Empty glumes narrow, IX. Sapling. 

B. Peduncle recurved (goosenecked) or sometimes erect. 

Panicle black, glumes awned. X. Gooseneck. 

The three varieties that have had most extensive cul- 
tivation are Amber, Orange, and Sumac. 

227. Amber, being the earliest of the three (90 to 
100 days), has been practically the only variety grown 
in the northern limits of sorghum culture — that is, 
north of Kansas and the Ohio River — ^and has been 
very popular in Kansas, the leading sorghum-growing 
State. 

Amber grows about 5 to 7 feet tall, wdth 8 to 10 leaves, 
being neither so tall nor so leafy as the other two varieties. 
The seed head is usually black and is loose or spreading, 
though it is somewhat variable in this respect. A number 
of selections have been made, the best known of which 
are : Minnesota Amber, which differs only in minor 
details ; Red Amber, the heads of which are red instead of 
black but which is otherwise similar ; and Folger's Early, a 
strain said to be especially desirable for sirup production. 
The various strains of Amber sorghum have been popular 
for forage because of the rather slender stems and early 



298 



COEN CBOPS 



maturity, these qualities facilitating the curing and im- 
proving the quality of forage. 




Fig. 99. — Amber sorghum. 



228. Orange sorghum is two to three weeks later in 
maturing (100 to 125 days) than is Amber. It is about 12 
inches taller, the stalk is heavier and the nodes are shorter, 



THE SACCHARINE SOEGHUMS 



299 



and the plant is more leafy. The variety name refers to 
the deep orange color of the ripe heads. This variety is 
excellent for sirup pro- 
duction and it makes 
a heavy yield of for- 
age, especially on good 
land. However, for 
cured forage farmers 
object somewhat to 
heavy stalks, as they 
are more difficult to 
handle and cure. 
Orange sorghum is 
second in popularity 
to Amber and is grown 
principally from Kan- 
sas southward. 

Collier and Coleman 
are two varieties of 
the Orange sorghum 
type which are so sim- 
ilar to it that for all 
forage purposes they 
may be considered the 
same. The Colher is 
considered the better 
for sirup-making. 

229. Sumac sor- 
ghum derives its name 

from the very com- Fig. lOO.- Orange sorghum. 

pact red seed head, 

resembling the seed head of sumac. It is somewhat larger 

and perhaps later than Orange, but otherwise similar in 




300 



CORN CROPS 



appearance of plant. - For forty years this has been the 
most popular variety in the South, especially in the Pied- 
mont districts. It is now largely grown in Texas and 
Oklahoma also." 

230. Gooseneck is a very large, 
late-growing variety, adapted 
only to the South. Ten to fifty 
per cent of the heads are re- 
curved, or ''goosenecked." 





Fig. 101. — Sumac sorghum. Fig. 102. — Gooseneck 



sorghum. 



CHAPTER XXV 

THE NON-SACCHARINE SORGHUMS 

231. The non-saccharine sorghums, with the exception 
of broom-corn, are often called grain sorghums because 
their principal value is as grain producers rather than as 
producers of forage. As a group, they constitute the most 
drought-resistant grain and forage crops in cultivation. 
The five principal types of the non-saccharine sorghums 
are: (1) Kafir, (2) Durra, (3) Shallu, (4) Kowhang, (5) 
Broom-corn. 

Historical. — • The non-saccharine sorghums are very 
generally cultivated throughout Africa, southwest Asia, 
India, and Manchuria, but are not cultivated extensively 
in Europe. In general, the kafir types dominate in South 
Africa, the Durra types in North Africa, southwest Asia, 
and India, and the Kowliang types in Manchuria. Shallu, 
the least important of the five principal groups, is grown as 
a winter crop in India, and the same type has been reported 
as grown in a limited way in Madagascar and at several 
points in Africa. 

232. The Durra group (spelled also dura, durah, doura, 
dhoura, and other ways) is the most important in the Old 
World. It should be noted, however, that there are three 
general groups of the durra sorghums, only one of which 
is important in the United States : (1) The types grown in 
central and northeast Africa are tall, large-seeded, and 
late-maturing, furnishing both forage and grain ; (2) those 

301 



302 



CORN CROPS 



• # t - 



# # # ^ § 



4 m * 






s # ^ 



& 9 

# # # 

# # # 

# t # j» 



THE NON-SACCHARINE SORGHUMS 303 

of North Africa are shorter, early, comparatively low in 
forage and high in grain production, and the grain is flat 
and of medium size ; (3) those of India have comparatively 
small heads and seeds, the seeds not decidedly flat ; they 
produce both forage and grain, but are too large and late- 
maturing for culture in the United States. 

The second group has thus far furnished most of the 
varieties that have found a place in United States agricul- 
ture. The probable reason is that grain sorghum could 
not compete with maize in the corn-growing belt. There 
was, however, a distinct demand for crops adapted to the 
Great Plainc, a region too dry for the culture of corn. The 
sorghums from the i lore humid regions of the Old World 
have not always been drought-resistant, and in most 
cases are too late in maturing. Most of the kafirs and 
durras meeting the requirements of drought resistance 
and a short maturing season have come from the drier 
regions of North Africa and the high plains of South Africa. 

233. Introduction in the United States. — The cultiva- 
tion of non-saccharine sorghums dates from the intro- 
duction of White Durra and Brown Durra into California 
in 1874 and the introduction of kafir in 1876, but they 
were not generally distributed until about ten years later. 

234. Region where cultivated. — ^The ^^grain sorghums" 
are cultivated for grain and for forage. They are not so 
desirable for forage alone as are the sweet sorghums ; the 
fodder is coarser and lacks the sweet sugars in the stem, 
being less palatable. They are commonly harvested for 
both grain and forage. As a grain crop they cannot com- 
pete with corn in the regular corn-growing belt, and there- 
fore the principal grain-sorghum belt lies just west of the 
corn-growing belt, following in general the line of 25- 
inch rainfafl on the east and extending west to the Rocky 



304 



COBN CBOPS 



Mountains; the belt includes also southern California 
and Utah. The accompanying chart ^ (Fig. 104), prepared 




/IRC/I TO yVH/CH M/LO /S /VOW /!£>/) PTSO 

/1R£/) /A/ WMCH TH£ /IMPT/^S/L/Ty OF M/LO /S BE/f/G TESTeO. 

Fig. 104. — This map made to show the distribution of milo ; also shows, 
approximately, the area where the culture of all sorghums are of most 
importance. 

to show the area of Milo culture, outlines the probable 
area of grain-sorghum culture. 

235. Statistics of culture. — The latest complete data 
on the grain sorghum acreage is for the census year 1909. 
About 90 per cent of the acreage was in three states, Texas, 
Oklahoma, and Kansas, with the remainder largely in New 
Mexico and Cahfornia. The most recent statistics (Crop 
Reporter, December, 1918) do not include data for 
California, although it is believed there has been a con- 
siderable increase in acreage. 

The principal states with comparative acreage for 1909 
and 1918 are as follows : 

1 U. S. Dept. Agr., Farmers' Bui. 322, p. 11. 



THE NON-SACCHARINE SORGHUMS 



305 



Grain Sorghums 



State 


Acreage 


Yield per Acre 


1909 


1918 


1918 


1917 


1916 


Kansas . . . 


388,495 


2,139,000 


9.4 


8.2 


10.0 


Texas .... 


573,384 


1,605,000 


15.0 


11.5 


22.0 


Oklahoma . . 


532,515 


1,526,000 


10.0 


16.0 


7.0 


Colorado . . . 


11,971 


92,000 


19.0 


15.0 


10.0 


New Mexico . 


63,570 


199,000 


18.0 


18.0 


22.0 


Arizona . . . 


801 


58,000 


28.0 


33.0 


35.0 


California . . 


44,308 











The rapid increase in acreage since 1909 is the best 
testimony as to the value of grain sorghums. 



,.^^:^ 

^^^-f*" 










^^^! 



-1^*;^^ 

*%%*^ 



Fig. 105. — Two heads of Milo, showing good and poor types. 



306 



CORN CBOPS 



The comparative acreage and value of non-saccharine 
sorghums compared with corn in Kansas and Oklahoma, 
as compiled in Bulletin 203, Bureau of Plant Industry, 
United States Department of Agriculture, is given 
above. 

236. Classification of non-saccharine sorghums. — 



Pith juicy : 

(Very juicy, sweet = Sorgo.) 

Juice scanty, subacid or somewhat sweet or dry in 
certain varieties. 
(1) Heads erect, cylindrical, spikelets oval, small, 
3-4 mm. wide, 
(a) Seeds wMte : 

Glumes greenish white, some darker. 

I. White Kafir. 
Glumes black or nearly. 

II. Blackhull Kafir. 
(6) Seeds red : 

Glumes deep red to black. 

III. Red Kafir. 



Kafir 
Group 



DURRA 

Group 



(2) Heads pendent but sometime secret, ovate ; 
spikelets broadly obovate, large, 4, 5-6 
mm. wide, 
(a) Seeds white : 

Glumes greenish white, silky, seeds flat- 
tened, awned. IV. White Durra. 
Glumes black, seeds smaller, less flattened, 
rare. V. Blackhull Durra. 

(6) Seeds yellowish to reddish brown : 

Glumes short, wrinkled, reddish to black, 

not silky ; seeds yellowish brown ; 

florets awned. VI. Yellow Milo. 

Glumes as long as seeds, greenish white, 

seeds reddish brown, not awned. 

VII. Brown Dxirra. 



THE NON-SACCHARINE SORGHUMS 



307 



Broom- 
corn 
Type 



Pith dry : 

Head loose, 10-28 inches long; spikelets oval or 
obovate, small, 2.5-3.5 mm. wide, 
lemmas awned : 
Rachis one-fifth as long as branches. 

(a) Branches drooping, seeds reddish. XI. 
Broom-corn. 
Rachis more than two-thirds as long as head, 
(a) Branches of panicle drooping; glumes at 
maturity spreading and involute ; seeds 
white to buff (several varieties). 

VIII. Shallu. 
(6) Branches spreading but not drooping, 
glumes at maturity appressed, not in- 
volute ; seeds white, brown, or red. 
(Several varieties, corresponding to the 
red, white, and blackhuU varieties of 
Kafir and Durra. Also standard and 
dwarf.) IX. Kowliang. 

Head compact, erect or pendent, spikelets oval or 
obovate, small, lemmas awned : 
Rachis two-thirds as long as head. X. Kowliang. 



237. Dwarf varieties. — Dwarf varieties of almost all 
the principal types of grain sorghums have been developed 
during the past dozen years. The dwarf types are prac- 
tically all earlier, by a week or ten days, than the standard 
sort. As a rule, the dwarf varieties are recommended 
for the drier regions in preference to the standard sorts. 
They appear to be more capable of producing seed under 
adverse conditions. Dwarf varieties are also easier to 
harvest. In some cases they are short enough to be har- 
vested with the grain header. The yield of forage, how- 
ever, is low. 

238. Standard varieties. — Where there is sufficient 
rainfall and the soil is good, the standard sorts are recom- 
mended in preference to the dwarf varieties. Under 



308 



COBN CROPS 



favorable conditions they usually yield more grain, and 
always more forage. 

239. Kafir. — The four principal types of kafir are red, 



white, pink, and blackhull. 



The heads are erect, in 
contrast to the durra 
group, in which the heads 
are mostly reciirved, or 
" goosenecked." The 
white and blackhull va- 
rieties both grow about 
5 to 6 feet high, while the 
red is 8 to 12 inches taller. 
The white and red varie- 
ties were first introduced. 
The white variety, how- 
ever, was not satisfactory 
because of its not matur- 
ing well, and the head was 
not always exserted from 
the leaf sheath, thus induc- 
ing rot in damp weather. 
The red variety matured 
properly and soon became 
more popular. 

The objection to Red 
Kafir was the astringent 
taste of the seed coat, 
common to all kafirs with 
a colored seed coat. The 
blackhull, a white-seeded 
variety, appears to be a later introduction, having attracted 
attention about 1896. It had all the good quahties of 
Red Kafir, and in addition the seed was not astringent. 




Fig. 106. — Plant of Blackhull Kafir. 



THE NON-SACCHARINE SORGHUMS 



309 



This variety probably furnishes nine-tenths of the kafir 
crop to-day. In recent years Pink Kafir has also super- 
seded Red Kafir and is 
grown in sections too 
dry for standard Black- 
hull, or on poor soils. 

240. Durra. — The 
characteristics of this 
group are that the 
heads are mostly 
" goosenecked " and the 
seeds are large and flat. 
The extensive culture 
of non-saccharine sor- 
ghums in this country 
began with the intro- 
duction of Brown Durra 
and White Durra into 
California in 1874, but 
the culture did not be- 
come general in the 
Great Plains region un- 
til about 1890. 

The White Durra is 
commonly known as 
*' Jerusalem corn," and 
sometimes as " Egyp- 
tian rice corn." The 
Brown Durra is often 
called ''Egyptian ^ ,^„ ., _„ ^ 

^-^ ^ Fig. 10 / . — vV in te Kafir Corn. 

corn. 

White Durra is little grown, as it is frequently injured 
by insects and diseases. The grain also shatters badly. 




310 



CORN CROPS 





Fig. 108. — Upright Milo head. 



Fig. 109. — Pendent form of 
Milo head. 



THE NON-SACCHARINE SOBGHUMS 



311 



Brown Durra has continued in cultivation especially 
in southern California and Texas. The total area of White 
and Brown Durras was estimated at 50.000 to 60,000 acres 
in 1908.1 

241. Milo, or Yel- 
low Milo, was intro- 
duced about 1885, ten 
years later than the 
White and Brown 
Durras, but it quickly 
became the most pop- 
ular of the group, the 
area in 1908 being 
estimated at 300,000 
acres. This variety 
will mature in 90 to 
100 days and is 
adapted to culture as 
far north as south- 
western Nebraska. 
In addition to the 
standard varieties, 
there is now a dwarf 
variety well suited to 
cultivation for grain 
production. 

Compared with 
kafir, the durras are 
better adapted as 
grain producers but 
not so well suited for 
forage production. 

1 U. S. Dept. Agr. Bur. Plant Indus., Bui. 175, p. 34. 




Fig. 110. — Yellow Milo. 



312 CORN CROPS 

Milo is the best suited of all the sorghums for grain pro= 
duction. Early varieties of milo have been developed by 
selection, whicK adapts it to a wide range of conditions, 
and this plant, together with Blackhull Kafir, is the best 
of the sorghums for grain production. 

The milos, being about three weeks earlier in maturing 
than the kafirs, have two distinct advantages : in Okla- 
homa and Texas they can be planted early and will more 
nearly mature before the severe midsummer drought; 
also, they may be grown farther north and at higher alti- 
tudes. 

242. Feterita was introduced from the Sudan, Africa, 
a hot dry country south of the Sahara Desert, in 1906. 
It is an early grain sorghum, maturing in eighty to ninety- 
five days, and belonging to the durra group. Feterita is 
adapted to about the same conditions as Dwarf Milo, but 
is somewhat more drought resistant under very dry con- 
ditions, and also is less injured by chinch bugs. 

The seed shatters readily when ripe. The stalks are 
small, rather dry and are inferior as a fodder crop. The 
seeds being rather soft, rot easily in the soil, often resulting 
in poor stands. Feterita in competition with Dwarf 
Milo can hardly be rated as equal, but due to its great 
drought resistance, it is rated as a close second and will 
retain a place in cultivation. 

243. Shallu. — This plant is of recent introduction. 
The stalks are tall and slender, with large loose and open 
panicles, approaching broom-corn in type. The plant 
comes from India, where it is cultivated as a winter crop, 
being sown in October and harvested in March. It is 
grown for both seed and forage. Seed of this was in- 
troduced and tested by the Louisiana Agricultural Experi- 
ment Station about twenty years ago. It is occasionally 



THE NON-SACCHARINE SORGHUMS 313 

grown from Kansas to Texas. It has acquired several 
local names, as California wheat, Egyptian wheat, and 
Mexican wheat. 

244. Kowliang. — In both India and China the sor- 
ghums are commonly classed with millets. " Kowliang,'^ 
or '^ tall millet," is a Chinese name given to distinguish this 
variety from the common smaller millets (Panicum and 
Chsetochloa). The three colors of seed and glume found 
in kafirs and durras are found also in this group, namely, 
brown seeds with black glumes, white seeds with black 
glumes, and white seeds with white glumes. There are 
varieties of both dwarf and standard size, 4 to 11 feet 
high. 

Kowliang comes from northeast China and the adjacent 
territory of Manchuria, 38° to 42° north latitude — the 
farthest north of any region where sorghums have been 
an important crop for any great length of time. They 
are extensively cultivated in this region for grain and 
forage and the stems are used for fuel. 

All varieties are early-maturing, and, being already 
adapted to a region farther north than any other group 
of sorghums except the Early Amber varieties (the original 
Amber type also came from China), they should be adapted 
to a similar latitude in the United States. They have not 
been extensively tried in this country, but the early dwarf 
stocks give promise of furnishing a good foundation stock 
for the development of grain .sorghums in the northern 
half of the Great Plains. They could not replace Early 
Amber sorghums as a forage crop. 

245. Hay sorghums. — Recently there have been in- 
troduced several jQne-stemmed sorghums, very leafy and 
resembling very coarse grasses in general appearance. 
They are similar to the well-known Johnson grass of the 



314 COBN CB0P8 

South, but do not have the strong underground perennial 
rootstalks. Hay sorghums belong to the non-saccharine 
group. 

246. Sudan grass has been extensively tried as a forage 
crop. It will produce a hay crop in seventy to eighty 
days, sprouts up readily from the roots, and in the South 
will yield two to three cuttings in a season. Sudan grass 
is usually sown broadcast and handled as a hay crop. It 
will not yield as much as the larger sweet sorghums as a 
rule, but due to its quick growth will probably find a per- 
manent place as a forage crop in the northern part of the 
great plains, and as a short season catch crop farther south. 



CHAPTER XXVI 
CULTURAL METHODS FOR SORGHUMS 

Sorghums are grown for four distinct purposes : (a) as 
a grain crop primarily, (6) as a forage crop, (c) for sirup 
manufacture, and (d) for broom-corn brush. 

The land to be chosen would be similar in each case, 
but the principal difference in cultural methods would 
come in method of sowing and harvesting. 

Because the sorghums will grow on poorer and drier 
land than any other of our cereals is to be taken as an 
indication not that they naturally prefer such conditions, 
but rather that they are capable of withstanding greater 
hardships than other crops. Consequently, the culture 
of sorghums may extend beyond the limits of common 
cereals; but, on the other hand, they will respond as 
readily to manuring and to favorable environment as 
will any plant, on good, rich land producing six to seven 
tons of cured forage per acre. 

Preparation. — The land is prepared much as for corn. 
The plowing may be done in the fall or in the spring. 
As planting does not take place until rather late — two 
to four weeks after corn, — there is ample time for spring 
preparation of the soil. 

GROWING SORGHUMS FOR GRAIN 

247. Varieties. — Blackhull Kafir, Milo, Red Kafir, and 
Brown Durra, in the order named, are the principal sor- 
ghums grown for grain. 

315 



316 



CORN CEOPS 




Fig 111. — Heads of Sudan Durra, from San Antonio, Tex. On left in 

SeX'rih 'i ''^"i''\ ^^^^' ^"* '^^^"^ ^^ ^i^^^' On right, in flower 
September 1, and almost sterile, due to midge. 



CULTURAL METHODS FOR SORGHUMS 317 

248. Time of planting. — Grain sorghums are usually 
planted soon after corn; the time ranging from March 
to June in the Southern States, while as far north as 
Nebraska the planting must be as early as possible in 
order to insure maturing. Planting in Nebraska practi- 
cally coincides with corn planting, about May 10. 

In the San Antonio region of Texas it has been found 
necessary to plant very early in order to avoid the sorghum 
midge, an insect that becomes very numerous in June 
and practically prevents all seeding from that date on. 
In order to avoid the midge, planting must be early. 
According to one experiment reported in 1911, eleven va- 
rieties of grain sorghums planted on March 4 yielded 23.1 
bushels, while early varieties only, planted on March 15, 
gave only profitable yields, and no varieties planted on 
April 1 were profitable.^ 

249. Rate of planting. — Grain sorghums are usually 
planted in rows 3 or 3^ feet apart ; the plants 6 to 8 inches 
apart for the milos and durras, and 8 to 10 inches for 
kafirs. On very fertile soils the planting should be 
thicker than this. The amount of seed required will be 
3 to 8 pounds per acre. With durras a higher percentage 
of the heads " gooseneck," or recurve, when planted thin 
than when planted thick. 

250. Methods of planting. — Corn-planting machinery 
is generally used for sorghums, the only change necessary 
being to use special plates for dropping or to adapt the 
corn-dropping plates. The corn-planting plates can be 
adapted by filMng the holes with lead and boring out to 
the right size. Grain sorghums are always drilled. 

Listing is a method common in regions of low rainfall, 

1 Grain Sorghum Production in the San Antonio Region of Texas, 
U. S. Dept. Agr., Bur. Plant Indus., Bui. 237. 1912. 



318 



CORN CROPS 



but in regions of higher rainfall and heavy soils surface 
planting is better. When planted in a lister furrow the 
seed should not be covered deeper than is necessary to 




Fig. 112. — Plat of Milo selected for erect heads. 



insure good germination, as it rots very easily when planted 
deep or when the soil is cold or wet. 

Surface planting is ordinarily done with the two-row 
corn-planter ; the grain drill is sometimes employed, how- 
ever, by using only every fourth or fifth hole. 

251. Tillage. — The same tools are used in general for 
cultivating sorghum as for corn, and in much the same 
manner. However, sorghum, especially when listed, is 
much slower in growth than corn for the first four weeks, 



CULTURAL METHODS FOR SORGHUMS 319 

and consequently more skill is required to clean out the 
weeds. Young sorghum is tougher and less likely to break 
than is young corn, which is an advantage, since it permits 
of the use of such tools as harrows and weeders oftener and 
longer than is the case with corn. With surface-planted 
sorghums, by the proper use of harrows and weeder it is 
often not necessary to give more than one thorough 
cultivation with the shovel cultivator. 

With listed sorgum, the harrow and lister cultivators 
should be used for the first cultivation. When the plants 




Fig. 113. — Field of White Kafir in shock. 

are 8 to 10 inches high a very thorough cultivation should 
be made with the cultivator, to be followed later by such 
shallow cultivation as is necessary to keep down weeds. 

252. Cutting. — When grown for grain the heads should 
be fully ripe. If cut for silage', the seeds should be in the 
soft dough stage, as the ripe seeds in silage are very likely 
to pass through the animal without digestion. 

The corn-binder is the best and most economical 
implement for harvesting on a large scale. With smaller 
areas the sled cutter is used, or the crop is cut by hand. 



320 CORN CROPS 

Grain headers are sometimes used for harvesting the 
heads of dwarf varieties. A large part of the crop, how- 
ever, is harvested by cutting off the heads by hand with a 
corn knife. The heads are usually thrown directly into 
a wagon box, driven along beside the cutter. 

253. Curing. — When the heads only are harvested, 
they are usually cured by piling in narrow ricks on dry 
ground, by storing in slatted bins, or ordinary corn cribs, 
or sometimes by spreading out on a layer of straw. The 
grain sorghum fodder, however harvested, should be set 
up in shocks until well cured. Precaution should be 
taken to set the base of the shock wide and to tie well 
about the heads. The heads being heavy, the shocks 
are very likely to fall over. 

Before threshing, the sorghum heads should be very dry, 
as the grain heats and spoils quickly when stored if at all 
damp. -This will require four to six weeks in the shock. 

254. Hauling and storing. — Where the fodder is fed, 
it is very common to haul from the field as used. Sorghum 
will remain in very good condition for several months 
when bound and set in large shocks. If not to be used for 
three months, it is usually better to haul and stack. 

When the stover and grain are to be fed separately the 
bundles are sometimes beheaded with a broadax or heavy 
knife. The heads are then stored in a dry place, to be 
fed whole or to be threshed. 

255. Threshing. — The whole bundles are sometimes 
run through an ordinary grain-thresher, or only the heads 
run in and the bundles then withdrawn. The labor is 
heavy in both cases and it is often considered better to 
behead the bundles and thresh only the heads. 

256. Yields. —The average yield in Kansas and Okla- 
homa is not equal to that of Indian com ; but in these 



CULTURAL METHODS FOR SORGHUMS 321 

states corn is raised in the part of the state having heaviest 
rainfall, and sorghum in the drier part. 

West of the 25-inch-rainfall line, grain sorghums will 
equal or outyield corn. The advantage increases as rain 
decreases. Yields of twelve to twenty bushels of grain 
sorghum are often harvested when corn is a failure from 
drought. Twenty bushels per acre is considered an aver- 
age crop and forty bushels per acre a good crop. Yields 
of seventy bushels have been known. 

GROWING SORGHTJMS FOR FORAGE 

257. Sweet sorghums are used more extensively when 
grown primarily for forage than are the non-saccharine. 

Since the foliage of all sorghums remains green until 
the heads are mature, a fair quality of coarse forage is 
secured when sorghurns are grown for grain. About one- 
half the sorghum crop is sown primarily for fodder, to be 
cut before heads are ripe and cured as fodder or hay. 

258. Time of planting. — In the Gulf States sorghum 
is often sown early so that the crop may be cut two or 
three times, though sowing may continue for several 
months. In the Central States sowing is usually after 
corn planting, generally in the month of June. 

259. Rate of planting. — Sorghum for forage is either 
sown thick in drill rows about 3 feet apart and cultivated, 
or sown close, either broadcast or with the grain drill. 

When sown in rows to be cultivated, the methods are 
similar to those for growing grain except that about 15 
pounds of seed per acre is used instead of 2 to 5 pounds. 

When sown broadcast, one to two bushels per acre of 
seed are used ; the thinner sowing is done on poorer land 
or in a dry climate, and the thicker seeding under the most 
favorable conditions. 



322 



CORN CROPS 



260. Methods of planting. — Which of the two methods 
shall be employed — drilling or broadcasting — depends 
on circumstances. In regions of low rainfall, drilling in 
wide rows and cultivating is the surer method, but in 
more humid regions there is little difference in 3deld. 
On the other hand, drilling in rows increases the cost 
because of the amount of cultivation necessary. The 
fodder is also coarser. 

Harvesting forage sorghum . 

261. When cultivated in rows the best method of 
harvesting is with a corn-binder. The bundles are set up 
in small shocks to cure. In four to six weeks several 
small shocks may be set together in large shocks, which 



ij 



.U^j 







^fm- 



s^^ 



7 mm 



Fig. 114. — Cutting sorghum forage with a mower. 



CULTURAL METHODS FOB SORGHUMS 323 

are securely tied near the top and left in the field to be 
hauled as used. A better method is to stack in large 
stacks, but care must be observed that the fodder is well 
cured before stacking. 

When sown broadcast the crop is usually cut with a 
mower and handled as coarse hay, or cut with the grain- 
binder. 

When cut with a mower a stubble of 6 inches should be 
left. This tall stubble facilitates drying, and also gath- 
ering the heavy fodder with a hayrake. Heavy sorghum 
hay dries very slowly and should be left for one to two 
weeks in the swath before raking and cocking. It should 
be thoroughly cured in the cocks before stacking. 

262. An average yield of cured fodder varies from 3 to 
6 tons per acre in humid regions, and half as much in dry 
regions. Very heavy yields of 10 tons per acre have been 
reported from one cutting. Where sorghum is cut two or 
three times a season, as in the South, the relative yield of 
the different cuttings depends on the method of handling. 
If the first cutting is allowed to become quite ripe, the fol- 
lowing cutting will be light ; but if the first crop is cut 
quite green, the second cutting may be as heavy as, or 
heavier than, the first. 

263. Seed crop. — Twenty-five to thirty bushels of 
seed per acre is considered an average yield. All sorghum 
sown in rows for fodder or planted thin for sirup-making 
produces a good crop of seed. Most of the commercial 
seed of sweet sorghums comes from this source. 



CHAPTER XXVII 
UTILIZING THE SORGHUM CROP 

In Asia and Africa the grain of sorghum is utilized 
principally as human food, in the United States as stock 
food. 

The seed coat is hard and rather indigestible, therefore 
all sorghum grain fed to live stock should be ground. 

264. Composition. — The composition of kafir is shown 
by the following summary : ^ — 

Food Constituents in Kafir. In Fresh or Air-dry 
Material 





Water 


Ash 


Pro- 
tein 


Fiber 


Nitro- 
gen-free 
Extract 


Fat 


Authority 




Per 


Per 


Per 


Per 




Per 






Cent 


Cent 


Cent 


Cent 


Per Cent 


Cent 




Kafir (whole 
















plant green) . 


76.13 


1.75 


3.22 


6.16 


11.96 


0.78 


Penn. Station 


Kafir (whole 
















plant green) . 


76.05 


1.44 


2.34 


8.36 


11.41 


0.40 


N. Y. (Cornell) 

Station 


California : 
















Ave. all Durras 


11.09 


1.69 


9.62 


1.58 


72.99 


3.02 


Cal. Bui. 


Ave. all Kafirs 


12.44 


1.65 


9.49 


2.06 


70.79 


3.43 


No. 278 


Ave. all Kaoli- 
















angs . ■ 


10.78 


2.04 


10.23 


1.98 


71.42 


3.54 




Texas (Amarillo) 
















Ave. all Kafirs 


9.47 


1.75 


13.46 


1.56 


70.29 


3.39 


U. S. D. A. 
Farmers' Bui. 
972 


Ave. all Milos 


9.31 


1.61 


12.49 


1.48 


71.88 


3.22 





iCycl. of Agr. /F:387. 
324 



UTILIZING THE SOBGHUM CROP 325 

Kafir and other sorghum seeds are considered to be 
very starchy foods. For good results they require that 
some protein food, as alfalfa hay or cottonseed meal, be 
fed with them. Ten per cent cottonseed meal is sufficient. 
Kafir grain fed alone is also constipating, and this tend- 
ency is corrected by the addition of a protein food fed 
in connection. 

When fed to cattle, horses, and sheep, good results are 
secured, though pound-for-pound feeding experiments 
show sorghum to be not quite so valuable as corn. In 
general, for fat stock, 80 to 90 pounds of corn have been 
found to equal 100 pounds of kafir or milo when fed in 
comparison. 

265. Poultry food. — Sorghum seed is one of the best 
poultry foods and enters into a large proportion of these 
foods found on the market. It is considered superior to 
corn. For poultry the seed need not be ground but is fed 
whole, either threshed or in the head. 

266. Soiling or green feed. — Sorghum is probably the 
most popular crop to cut and feed green. The sweet 
sorghums are used principally for this purpose. The 
superiority of sorghum for this use lies in its large yield, 
its sprouting up from the roots so that the crop may be 
cut several times in succession, and its drought resistance. 
Sorghum will remain green and growing under drier 
conditions than will other forage crops, furnishing succu- 
lent food at the time it is most needed. 

For green feeding it is usually drilled very thick, in 
rows 3 feet apart. 

An acre of green sorghum producing 12 tons will feed 
twenty head of stock for twenty days, allowing 60 pounds 
per head each day. 

267. Pasture. — Sorghum is used considerably as a 



326 COBN CROPS 

pasture crop. For this purpose it is sown rather thick, 
2 to 3 bushels per acre. Stock is turned in when the crop 
is 3 to 4 feet high. 

For pasturing, the field should be divided into lots and 
enough stock should be turned in to eat down the crop 
in about two weeks. The stock should then be removed 
to another lot and the pasture given four to six weeks to 
grow up again. This would require three to four lots. 

It is estimated that one acre will furnish grazing for 
the equivalent of one animal for one hundred days, or 
ten animals for ten days. 

268. Sorghum mixtures for pasture. — For pasture 
purposes German millet is sometimes mixed with sorghum 
and gives good results. Cereals have been used as a 
mixture, Jte>ut it is doubtful whether they add to the value 
as pasture. In the South, it has been recommended to 
mix sorghum and cowpeas, for both forage and pasture. 
Cowpeas give a better-balanced ration. For pasture 
the sorghum and cowpeas should be drilled in rows about 
8 to 12 inches apart, in alternating rows. 

269. Sorghum for silage. — Within the corn-belt, sor- 
ghum compares favorably with corn as a silage crop. 
In regions of less than 25 inches rainfall, sorghum will 
probably come to be the most important silage crop. 
In the South, also, it is likely to supersede corn for silage, 
especially where the crop is to be grown on rather poor 
land. 

Sorghum silage is more difficult to preserve than corn, 
being more likely to ferment. When well preserved it 
appears to have a feeding value about equal to that of 
corn silage, though very little experimental work on 
this point has been done. Sorghum for silage is now in 
extensive use in many places in the Southern States. 



UTILIZING THE SORGHUM CROP 327 

270. Sorghum poisoning. — Sorghum pasture under 
some conditions is a virulent poison. This is due to 
prussic acid forming in the leaves under certain condi- 
tions. The conditions favoring the development of prussic 
acid seem to be hot, clear, and dry weather, producing 
a stunted growth. Poisoning is most common in semiarid 
regions. When conditions are right for developing poison, 
the sorghum should be pastured with caution, as the poison 
acts quickly and there is no known remedy. Cattle 
should not be pastured on stunted or drought-stricken 
sorghum. Where it is desired to test the pasture, prob- 
ably the best way is to allow only a single animal to graze 
che field for a day or two. 

When poisonous sorghum is cut and allowed to lie 
until wilted, the poisonous property entirely disappears. 



CHAPTER XXVIII 
SORGHUM FOR SIRUP-MAKING 

As discussed heretofore (see page 296), sorghum has 
had an extensive use in the United States for sirup 
manufacture. The process of sirup-making is .so simple 
that nothing more is necessary than a roller press for 
extracting the juice, and a single evaporating pan. In a 
few cases rather extensive plants have been established, 
but most of the sirup has been made in small local plants. 

271. For sirup the sweet sorghums are used, as Amber, 
Orange, Sumac, and Gooseneck. There are strains of all 
these varieties selected for sirup-making. (See descrip- 
tion of these varieties, pages 297-300.) 

272. For sirup the sorghum is planted and cultivated 
practically as described for the culture of grain sorghums. 

273. Time of harvesting. — The sugar content of sor- 
ghum at different stages of growth as determined by Collier, 
the result of 2740 analyses, is given as follows : ^ — 

Sugar Content of Sorghum at Different Stages of Growth 



Stage of Cutting 


Sucrose 


Invert Sugar 


Panicles just appearing . . 
Panicles entirely out . . . 
Flowers all out . . . = . 

Seed in milk 

Doughy, becoming dry . 
Dry, easily split .... 
Hard 


Per Cent 

1.76 
3.51 
5.13 

7.38 

8.95 

. 10.66 

11.69 


Per Cent 
4.29 

4.50 
4.15 
3.86 
3.19 
2.35 
1.81 



1 Sorghum Sirup Manufacture. U. S. Dept. Agr., Farmers' Bui. 
^77 .-12. 

328 



SORGHUM FOB SIRUP-MAKING 329 

274. Sorghum increases not only in total weight until 
mature, but also in the percentage of sugar. The seed 
should reach a hard dough stage before cutting. 

Stripping. — For best results the leaves should be 
stripped. This is done while the canes are standing. The 
canes are often pressed without removing the leaves, but 
if this is the case, the yield of juice is less and the im- 
purities are much greater. 

Cutting. — The canes are cut by hand or with a corn- 
binder. In hot weather, cutting should be done not 
more than two days before grinding, as there is danger of 
fermentation developing. In cool fall weather, however, 
canes are often kept in large shocks for one to two weeks 
after cutting. 

When a heavy frost occurs the sorghum should be cut 
and placed in large shocks at once. If it is to stand for 
some time, both leaves and heads should be left on. In 
large shocks, with cool weather the sorghum may be kept 
with little loss for three or four weeks. 

A heavy freeze will do no harm provided the cane can 
be ground at once upon thawing ; but after thawing it is 
likely to go out of condition in a very short time. 

275. An average yield of green sorghum would be 8 to 
10 tons, though it may vary from 5 to 15 tons. 

The yield of sirup depends on the kind of mill, quality 
of the sorghum, and quality of the juice. 

A poor mill may extract only 30 per cent of the total 
juice, while with a good three-roller mill 60 per cent of the 
original weight may be extracted as juice, or 1200 pounds 
to a ton of canes. 

Juice varies in quality, containing 8 to 15 per cent of 
sugar. The juice is concentrated by boiling until it con- 
tains about 70 per cent of solid matter and 30 per cent of 



330 CORN CROPS 

water. The amount of sirup produced from a ton of 
canes is therefore very variable. 

In general, a ton of canes will give 700 to 1200 pounds 
of juice, which in turn will yield 10 to 30 gallons of sirup, 
according to quality. 

276. The manufacture of sorghum sirup consists of three 
steps: (1) extraction of juice; (2) clarification of the raw 
juice ; (3) evaporation of juice. 

The extraction is done with heavy roller presses of either 
the two-roller or three-roller type. The juice is then 
run into settling tanks, where impurities in suspension 
are allowed to settle out. 

The clarification is accomplished in some cases by 
merely allowing the raw juice to settle for some time. 
Settling is hastened by heating. Sometimes fine yellow 
clay is added, which aids in settling. When the juice is 
somewhat acid, lime also is added to the heated juice. 
After clarification the clear juice is drawn off to be con- 
centrated. 

Concentration takes place in large, shallow pans, where 
the juice is kept boiling by a well-regulated fire. Ordi- 
narily the pan is divided into compartments, the boiling 
juice flowing slowly in a thin layer from one end to the 
other. By the time the outflow is reached, the juice 
should be concentrated into sirup. In very small plants 
the juice is merely boiled down in kettles. 



CHAPTER XXIX 

BROOM-CORN 

Broom-corn belongs to the non-saccharine sorghums, 
resembhng Shallu or Kowliang more than others. It is 
characterized by very short rachis and long, slender, 
seed-bearing branches. The plant is grown principally 
for the seed head, or '' brush," having practically no forage 
value. 

277. Historical. — The origin of broom-corn is not 
known, though it was cultivated and used for making 
brooms two hundred and fifty years ago^ in Italy, where 
it apparently had its first general culture. References are 
made to its culture in the United States about the year 
1800. The following statement appears regarding it in 
a book entitled '' The Pennsylvania Farmer," published 
in 1804 : 2 "A useful plant, the cheapest and best for 
making brooms, velvet whisks, etc. The grain for poultry, 
etc., a few hills or rows of it in the garden or cornfield 
suffice for family purposes." 

While its value was thus recognized, its culture did not 
become important until several decades later. 

278. Statistics of culture. — During the past forty 
years, broom-corn culture has developed rapidly, as shown 
by the crop acreage for the past four census years : — 

Yeak Acres Pounds 

1879 29,480,106 

1889 93,423 38,557,429 

1899 178,584 90,947,370 

1909 326,102 78,959,958 

1918 3 333,000 116,000,000 

1 Mentioned by Casper Bauhin as used for this purpose in 1658. 

2 Twelfth Census, Vol. VI, Part II, p. 619. ^ Five states only. 

331 



332 



COEN CROPS 



The crop practically trebled 
in thirty years. 

Broom-corn culture has 
always been concentrated to 
certain rather hmited regions : 
Four States in 1879 — Illi- 
nois, Kansas, Missouri, and 
^ New York — produced 80 per 
cent of the crop. In 1889 
four States, the first three 
named above and Nebraska, 
produced 89 per cent of the 
crop. In 1899 the last-named 
four States and Oklahoma 
produced 90 per cent of the 
crop. 

In 1899 Ilhnois alone, which 
has been the leading State 
in broom-corn production for 
forty years, produced 66.7 
per cent of the entire crop 
:n the United States, while 
50.1 per cent of the entire 
crop was grown in three 
counties. 

During the ten years fol- 
lowing, 1889-1909, broom- 
corn culture moved to the 
West, centering in Okla- 
homa. In 1909 Oklahoma 
produced two-thirds the 



a Fig, 115. — Broom-corn, sorghum, and hybrid between the two : 
a, broom-corn ; 6, hybrid ; c, black-seeded sorghum. 




BROOM-COBN 



333 



acreage of the United States. The acreage and produc- 
tion of the broom-corn crop in the five principal states for 
the past two years, as indicated by the best estimates now 
available, is as follows : — 



Acreage, Acre- Yield, and Production in Tons op 
Broom-Corn in the United States, 1917, 1918. 



State 


Acreage 


Yield to the Acre 
Tons 


Production 
Tons 


1918 


1917 


1918 


1917 


1918 


1917 


Illinois . . 
Kansas . . 
Texas . . 
Oklahoma . 
Colorado . 


31,000 
58,000 
74,000 
140,000 
30,000 


30,000 
62,000 
48,000 
175,000 
30,000 


0.290 
.147 
.260 
.115 
.175 


0.296 
.150 
.175 
.150 
.155 


9,000 

8,'500 

19,200 

16,100 

5,200 


8,900 
9,300 
8,400 
26,200 
4,600 


Total . 


333,000 


345,000 


.174 


.166 


58,000 


57,400 



The acreage in Oklahoma has declined in recent years, 
as shown by the figures, with a corresponding increase in 
Colorado and Texas. 

279. Varieties. — Seedsmen fist broom-corn under at 
least a dozen variety names, but these names have little 
significance. There are two types, known as (1) stand- 
ard, normally growing about 12 feet high with a brush 
18 to 28 inches in length, and (2) dwarf broom-corn, 
growing 4 to 6 feet in height and producing a brush 12 to 
18 inches in length. 

The standard type is used for the manufacture of large 
brooms. 

While dwarf brush is also used to some extent in the 
manufacture of large brooms, the straw is generally too 



334 CORN CROPS 

fine and weak for this purpose. The dwarf type, however, 
is almost exclusively used in whisk brooms. There is 
some variation in different strains. Very often the large 
manufacturers keep on hand seed of the strains best suited 
to the needs of the trade, and are ready to supply growers 
with this seed. 

280. Brush. — The brush should be bright and of a 
uniform light green color. When the head does not fully 
exsert from the " boot," or upper leaf sheath, the base of 
the brush is likely to take on a red color, which is very 
undesirable. The discoloring is most common when con- 
siderable rain occurs during the maturing season. This 
is a very common fault of the dwarf variety and necessi- 
tates breaking over the brush as soon as it is well grown 
so that it will hang down. For this reason dwarf broom- 
corn is more successfully grown in rather dry climates, 
most of it at present being cultivated in Kansas and 
Oklahoma. 

Length of brush. — In general, the longer the brush 
the better, all other qualities being equal. There is some 
danger that very long brush may be coarse. Brush 
that is both fine and long is the most valuable. 

Rachis. — The rachis should be short, with no central 
" core " of stiff branches extending upward in the center. 

Shape of head. — The head should be broom-shaped 
rather than conical, with all branches approximately the 
same length. 

Flexibility. — The brush should be flexible and tough. 
This condition is attained both by proper climatic condi- 
tions and by proper harvesting. 

281. Culture of broom-corn. — The selection and prepa- 
ration of land, method of planting, cultivating, and so on, 
are no different in general from those in the culture of 



BBOOM-COBN 



335 



other sorghum crops. However, quaUty and uniformity 
in the crop is as important as yield, and more precaution 
must therefore be taken to have the land uniform, and the 




Fig. 116. — Poor and good heads of standard and dwarf broom-corn (after 
C. P. Hartley) : a, poor head of dwarf with large center ; b, head of 
dwarf inclosed in " boot " ; c, good grade of dwarf for whisks ; d, long 
head of dwarf with characteristic weakness at point x ; e and /, good 
grades of standard hurl ; g, good head of self-working ; h, poor grade 
of standard because of heavy center ; i, smutted head. 

stand uniform. Also, the cost of harvesting is much 
increased if the crop does not ripen so that it can all be 
harvested at one time. 



336 CORN CROPS 

Land. — Any productive soil will raise broom-corn. 
The principal consideration is that the soil be uniform. 
One reason why the culture of this plant has been so suc- 
cessful in central Illinois is because of the extensive areas 
of uniform soil. 

Planting 

282. Time of planting. — The planting of broom-corn 
usually begins about two weeks later than the planting 
of field corn and may be continued for a period of four 
weeks. In the Central States, planting is done from 
the middle of May to the end of June and harvesting begins 
the middle of August. It is often desirable to distribute 
the planting so that the harvesting will not come too 
much at one time. 

Method of planting. — The width of row varies from 
3 feet for dwarf varieties to 3J feet for standard varie- 
ties. The distance apart in row is 2 inches in dwarf 
and 3 inches in standard varieties. The planting should 
be uniform, as the brush will be too coarse where the stalks 
are thin, and undersized where the planting is too thick. 

Drilling is the ordinary method of planting. The ordi- 
nary corn-planter, with special plates for broom-corn seed, 
is satisfactory. 

Replanting thin places is not practicable, and thinning 
the stand is too expensive. It is, therefore, very impor- 
tant to take every precaution to secure a perfect stand at 
the beginning. It is hardly necessary to state that the 
land should be clean and in good tilth, and the seed should 
be carefully cleaned and of good germinating quality. 

283. Tillage. — • The same tools and methods of cultiva- 
tion that are successful with Indian corn are effective with 
broom-corn, except for the fact that broom-corn is more 



BROOM-CORN 



337 



delicate and grows slowly the first three weeks, necessitat- 
ing greater care and skill. 

284. Time of harvesting. — In order to get a good green 
color and tough, flexible brush, the corn must be cut quite 
green, or just as soon as the brush has reached full growth. 
The best time is when just past full bloom. 

If allowed to ripen, the brush loses color and becomes 
brittle, and the seUing price for such brush is often less 




Fig. 117. — Standard broom-corn, tabled and ready for hauling. 

than one-half that of high-grade stock. On the other 
hand, when allowed to ripen, 10 to 20 bushels of seed per 
acre is secured, which is valuable as a poultry and stock 
food. It is generally conceded that the loss in value to the 
brush is much greater than the value of the seed crop, 
although in California the seed crop is quite generally 
harvested ; but this is not customary in other places. 

Cutting the brush. — Dwarf broom-corn is usually 
" pulled," while the standard type is ^' tabled " and cut. 

Dwarf varieties are short enough so that a man can 

easily reach the heads; also, the base of the brush is 

inclosed in the '' boot," which must be removed. When 

the crop is uniform enough so that all can be pulled at one 

z 



338 COBN CHOPS 

time, the cheapest way is to pull and load directly on 
wagons. When it must be pulled twice, that harvested 
the first time over is laid on the ground and covered with 
leaves. It is not possible to get a uniform grade in this way. 
Standard broom-corn is first " tabled " and the heads 
are then cut by hand. In tabling, one man passes backward 




Fig. 118. — Threshing broom-corn seed heads or brush. 

between two rows, bending the stalks at a point about 
30 inches above the ground toward each other and across 
the row, so that the heads hang about two feet past the 
other row. Two men following cut off the heads and 
place them evenly, on every other table. Three men can 
harvest about two acres per day. Later, a team with a 
wagon passes over the empty tables and the brush is 
collected. 

Threshing and storing. — The heads are threshed 
directly from the field, or within a very few days after 



BROOM-COEN 



339 



cutting. The thresher removes all seeds, after which the 
brush is stored in drying sheds, in thin layers about 3 
inches deep. 

Bulking. — After drying for about three weeKfi^Sfush 
is piled in tiers, called '' bulking," for further drying. It 




Fig. 119. — Power baling press for broom-corn. 



then goes " through the sweat," which means merely that 
considerable natural heat is developed and the drying is 
hastened. 

Baling. — This should not take place until the brush 
is thoroughly dried. Good bales of brush are often very 
much damaged by heating and molding, as a result of 
baling before dry. A bale weights 300 to 400 pounds. 



340 



CORN CROPS 



285. Market grades. — Certain trade terms are applied 
in describing the qualities of broom-corn, which are well 




Fig. 120. — A bale of broom-corn. 

understood by those familiar with the stock. The fol- 
lowing data, prepared by C. P. Hartley, give trade terms 
and relative prices of different grades : — 

Cents per Pound 

Fair, crooked ... .....». = .. 1| 

Good, well-handled, crooked ....... 2 

Fair, medium, red-tipped . . . 3| 

Slightly tipp d, smooth growth ....... 4 

Good, green mooth, self-working 4| 

Choice, green, self-working carpet stock .... 5 

Fair, medium, sound hurl ........ 3| 

Good medium hurl 4 

Good, green, smooth, carpet hurl ...... 5 

Choice, green, smooth, carpet hurl ..... 5| 



BBOOM-CORN 341 

PUBLICATION ON SORGHUMS 

In this list, those publications to which no price is attached 
may be obtained without charge on application to the Secretary 
of Agriculture ; those priced may be obtained by remitting the 
stated sum to the Superintendent of Documents, Government 
Printing Office, Washington, D. C. 

United States Department of Agriculture, Washington, D. C 
Farmers' Bulletins. 

Saccharine Sorghums for Forage. Bulletin 246. 

Milo as a Dry-Land Grain Crop. Bulletin 322. Price, 5 
cents. 

Sorghum for Silage. Bulletin 334. 

Better Grain-Sorghum Crops. Bulletin 448. Price, 5 cents. 

The Best Two Sweet Sorghums for Forage. Bulletin 458. 

Kafir as a Grain Crop. Bulletin 552. 

Sorghum Sirup Manufacture. Bulletin 477. 

Use of Corn, Kafir, and Cowpeas in the Home. Bulletin 559. 

The Feeding of Grain Sorghums to Live Stock. Bulletin 724. 

Cereal Crops in the Panhandle of Texas. Bulletin 738. 

Shallu, or "Egyptian Wheat." Bulletin 827. 

How to use Sorghum Grain. Bulletin 972. 

Department Bulletins. 

Corn, Milo, and Kafir in the Southern Grain Plains Area: 

Relation of Cultural Methods to Production. Bulletin 242. 

Price, 5 cents. 
New Sorghum Varieties for the Central and Southern Great 

Plains. BuUetin 383. 
Studies on the Digestibility of the Grain Sorghums. Bulletin 

470. 
Grain Sorghum Experiments in the Panhandle of Texas. 

BuUetin 698. 

Bureau of Plant Industry Circulars. 

Feterita, a New Variety of Sorghum. Circular 122-C. Price, 

5 cents. 
Three Much-Misrepresented Sorghums. Circular 50. Price, 

5 cents. 



342 COBN CROPS 

Bureau of Plant Industry Bulletins. 

The History and Distribution of Sorghum. Bulletin 175. 

Price, 10 cents. 
The Importance of Thick Seeding in the Production of Milo. 

Bulletin 188. 
The Importance and Improvement of the Grain Sorghums. 

Bulletin 203. Price, 10 cents. 
Grain-Sorghum Production in the San Antonio Region of 

Texas. Bulletin 237. Price, 5 cents. 
The Kaoliangs : A New Group of Grain Sorghums. Bulletin 

253. Price, 15 cents. 
Cereal Experiments in the Texas Panhandle. Bulletin 283. 
Price, 10 cents. 

Bureau of Chemistry Bulletin. 

The Feeding Value of Cereals as Calculated from Chemical 
Analyses. Bulletin 120. Price, 10 cents. 

Yearbook Separate. 

The Grain Sorghums : Immigrant Crops That Have Made 
Good. Yearbook (1913). Separate 625. Price, 5 cents. 

Broom-Corn. 

Dwarf Broom Corns. Farmers' Bulletin 768. 
Standard Broom Corn. Farmers' Bulletin 958. 
Broom Corn Culture (Book), A. G. McCall. Orange Judd 
Pub. Co. 

State Bulletins. 

Growing Sorghum in Kansas. Kansas Bulletin 218. 
Grain Sorghums. California Bulletin 278. 



INDEX 



Acclimation, 117-121. 
Adaptation 

and improvement of corn, 74. 

of sorghum to dry climate, 28^ 
Adjustment of corn plants, 178. 
Air passages, 35. 
Alkali resistance, 290. 
Amber sorghum, 297. 
Andropogon halepensis, 279. 
Animal and insect pests of corn, 

221. 
Army worms, 220. 

Biological origin, 16. 
Biotypes, 109. 
Birds, 214. 
Breads, 252. 
Breeding 

close, narrow, broad, 102. 
Breeding plants, 94. 

how to conduct, 95. 

notes, 97. 

selection of ears, 96. 
Broom corn, 331-340. 

classification, 282. 

Calandra or y zee, 218. 
Carbon, in composition, 47. 
Chinch bugs, 220. 
Chinese maize, 24. 
Classification 

broom corn, 282. 

corn, 15, 20. 

by groups, 20-24. 

sorghum, non-saccharine, 282. 

sorghum, sweet, 281. 
Climatic factors. 

in growth of corn, 58-67. 

in growth of sorghum, 288. 



Composition of corn, 42. 

as affected by the rate planting, 183. 

as affected by time of cutting, 225. 

of parts of plant, 184, 226. 
Composition of sorghums, 324. 
Corn 

binder, 234. 

cost of production, 247. 

crossing biotypes, 111. 
214- varieties. 111. 

ear worm. 218. 

root-louse, 217. 

rootworm, 217. 

shows, 253. 

smut, 220. 
Corn crop, mineral requirements of, 

135. 
Coyote corn, 20. 
Crossing sorghums, 287. 

corn. 111. 
Crows, 214. 
Cultivation 

depth and frequency, 209. 

methods compared, 206. 

principles of, 197. 

tools for, 198. 
Cultivators 

for listed corn, 202. 

two-row, 200. 
Cultural methods, 158-275. 
Cutworms, 215. 

Dent corn, 22. 
Description 

corn plant, 26. 

sorghum plant, 283. 
Development of varieties, 78. 
Diplodia zece, 220. 
Diseases of corn, 220. 
343 



344 



INDEX 



Disk harrow, 167. 
Dominant characters, 105. 
Drainage, 157. 
Drought resistance, 286. 
Drying corn for shipment, 246. 
Durra, 299, 310. 
classification, 282.- 

Ear 

origin, 37. 

proportion of plant, 228. 

relative feeding value, 227. 

shrinkage, 245. 

storage, 242. 
Early culture of corn, 77. 

methods of modifying, 80. 
Ear worm, 218. 
Egyptian corn, 309. 
Energy, source of, 47. 
Environment 

effect on corn, 118. 
Erosion, 154. 

causes of, 155. 

•prevention of, 156. 
Euchlcena Mexicana, 16. 
European stalk borer, 219. 
Evaporation of water, 151. 

from soil under corn crop, 208. 
Exporation of corn, 4. 

Fertilization of corn, 52. 

of sorghum, 286. 
Fertilizers 

for corn, 138. 

formulas, 142. 
• increase due to, 141. 

use in rotation, 131. 

when profitable, 144. 

with farmyard manure, 133. 
Feterita, 312. 
Flint corn, 21. 

for North Carolina, 187. 

varieties, 189. 
Flowers of corn, 36. 
Fodder shrinkage in curing, 243. 
Forage 

corn, sowing for, 171. 

yield at different rates, 183. 

sorghum. 294. 
Fusarium, 220, 



Gibberella fusarium, 221. 
Gooseneck sorghum, 300. 
Grain sorghums, 301. 
Growth of corn, 48. 
climatic factors, 58-67. 
length of growing season, 59. 
relation of sunshine to, 61. 
rainfall to. 64. 
soils to, 68. 
Growth of sorghum 

relation of climate and soils, 288- 
289. 
Grub worms, 216. 

Harshberger. J. W., 15. 
Harvesting corn, 222-248. 

breeding plats, 97. 

comparative cost of methods, 241. 

cost of harvesting tops and leaves, 
232. 

time of, 224. 
Harvesting sorghum 

broom corn, 337. 

for forage, 322. 

for grain, 319. 

for sirup, 328. 
Hay sorghum, 313. 
Hermaphrodite forms, 24. 
History of corn, see Origin 

of early corn culture, 77. 

of sorghums, 279. 
Hoe cake, 252. 
Hominy, 249. 
Husker and shredder, 238. 
Husking fodder corn, 237. 
Hybridization of corn, 101-116. 

Importation of corn, 6. 
Improvement and adaptation, 74-84. 

of varieties, 85-92. 
Insects affecting corn, 215-220. 
Interculture, principles of, 197-213. 
International trade in corn, 4. 

Jerusalem corn, 309. 
July rainfall and yield, 66. 

Kafir, 308. 
Kowliang, 313. 



INDEX 



345 



Leaves of corn, 33. 

composition of, 184, 227. 

percentage, 226. 

stripping, 230. 

turgidity, 39. 
Lime, 147-149. 

application of, 134. 
■ effect of, 147. 
Lister, 168. 
Listing, 169. 

Manure, farmyard 

for corn, 130. 

value the ton, 132. 
Marketing, 245. 
Market movement, 11. 
Mass selection, 88. 

results with, 89. 
Meal, corn, 249. 
Mendel's laws, 104. 
Milo, 311. 
Mineral matter for corn soils. 135- 

150. 
Moisture in corn, 175. 

Natural selection, 83. 
Nitrogen for corn, 134, 146. 
Non-saccharine sorghums, 301. 

classification of, 291. 

region cultivated, 303. 

statistics, 304. 

Orange sorghum, 298. 

Organic matter of corn soils, 130. 

Origin of corn 

biological, 16. 

geographical, 15. 
Origin of sorghum, 279. 

geographical, 280. 

Pasture (sorghum), 325. 
Pedigree selection of corn, 89. 
Physiology of corn, 38. 
Physiology of sorghum, 286. 
Plant, corn 

description of, 26-37. 

number to the acre, 176. 

type of, 86. 



Planter's corn 

calibrating planter plates, 195. 

lister, 168. 

two-row check, 172. 
Planting corn, 161. 

checking and drilling, 172. 

depth of, 175. 

rate of, 176. 

on various soils, 180. 
time of, 173. 
width of rows, 182. 
Plowing for corn, 163. 
Pod corn, 20. 
Poisoning, sorghum, 327. 
Poison, for squirrels, 215. 
Pop corn, 21. 

products, 251, 
Preparation of land for corn, 161. 
Products, corn, 249-251. 
Production, broom corn, 331. 
Production of corn 

as related to climate and soils, 
54-73. 

causes of low, 70. 

continents. 2. 

countries, 2. 

development, 7. 

how maintained, 134. 

percentage, 3. 

restoring, 123. 

United States, 6. 

world's crops, 1-2. 
Production of non-saccharine sor- 
ghums, 304. 
Production of sorghum sirup, 295. 
Pseudomanes, 221. 
Pyrausta nubilalis, 219. 

Rate of planting corn, 176. 

on different soils, 180. 
Recessive characters, 105. 
Relation of climatic factors to growth, 
58. 

of cropping systems to yield, 122. 

of July rainfall to yield, 66. 

of soils to growth, 68. 
Relationship, degrees of, 101. 
Relative importance of corn, 1. 
Rhizopus, 221. 



346 



INDEX 



Rodents, 214. 
Root-louse, 217. 
Roots of corn, 26-30. 

depth, 176. 

prevent evaporation, 208. 

spread of, 28. 
Roots of sorghum, 285. 

in upper layers, 290. 
Rootworm, 217. 
Rotations for corn, 127. 
Run-off water, 151. 

Saccharine sorghums, 293-300. 

classification, 296. 

introduction, 293. 

sirup, first grown for, 294. 
gallons produced, 295. 

sirup-rc^king, 328-330. 
Seed corn 

c\u-ing sweet corn, 264. 

germination tests, 192. 

grading, 195. 

preparation of, 190. 
Selection of corn 

for composition, 91. 

mass, 88. 

natural, 83. 
Self-fertilization, 107. 
Shallu, 312. 
Shocks, size of, 235. 

tjong, 237. 
Show corn, 253-258. 
Shredding fodder, 238. 
Shrinkage of ear corn, 244. 

of fodder in curing, 243. 

of silage, 243. 
Silage 

from sorghima, 326. 

growing corn for, 212. 

shrinkage of, 243. 

time of harvesting, 229. 
Sirup-making, 328-330. 
Smut of corn, 220. 
Soft corn, 22. 
Soils 

as related to growth, 68. 

classification of corn soils, 70. 

non-saccharine sorghums, 301. 

saccharine sorghums, 293. 



Sowing corn for forage, 171. 

Squirrels, 214. 

Stalk borer, Eiu-opean, 219. 

Stalk cutter, 162. 

Stomata, number, 35. 

Stover, feeding value of, 229. ' 

relative yield, 228. 
Style, 51. 
Subsoiling, 166. 
Sudan grass, 314. 
Sunlight, intensity of, 62. 
Sweet corn 

contract with growers, 266. 

description of, 22. 

forcing sweet corn, 273. 

market for, 270. 

products of, 251. 

seed, 263. 

varieties, 262. 

Teosinte, 18. 
Tillage 

comparison of methods, 206. 

depth and frequency, 209. 

machinery, 197. 

reasons for, 205. 
TiUers, 33. 

economic value of, 179. 

factors affecting, 179. 
Tripsacum dactyloides, 16. 
TuU, Jethro, 205. 
Type of ear, 85. 
Type of plant, 86. 
Types of corn for different sections, 

185. 

Uses of corn, 249-252. 

Ustilago zeoe, 220. 

Utilizing the sorghum crop, 324. 

Value of principal crops, 7. 
Varieties of corn 

development of, 78. 

for different regions, 187. 

improvement, 85. 

production by selection, 83. 
Varieties of sorghum 

broom corn, 331. 



INDEX 



347 



Varieties of sorghum — Continued 

for grain, 301. 

sweet sorghums, 293. 
Verticillum, 221. 



Water 


224. 


absorption, 45. 


Yields, sorghum 


given off, 45. 


broom corn, 3 


loss from fallow soil, 207. 


forage, 323. 


loss of, 35. 


grain, 320. 


regulating supply of, 151-157. 


sirup, 329. 


required by months, 152. 




required for corn, 65, 151. 


Zea Mays 


Weeds 


amylacea, 22. 


clearing, 168. 


canina, 20. 


effect on jdeld of corn, 208. 


curayua, 24. 


Wireworms, 216. 


everta, 21. 




hirta, 23. 


Xenia, 103. 


indentata, 22. 




indurata, 21 f. 


Yellow Milo, 311. 


japonica, 23. 


Yields, corn. 


saccharata, 22. 


ability of corn to, 57. 


tunicata, 20. 



Yields, corn — Continued 

relation to cropping system, 122. 

to the acre, 7. 

to the acre, forage, 183. 

when harvested at different dates. 



Printed in the United States of America. 



